bionic (5) gmt.conf.5gmt.gz

Provided by: gmt-common_5.4.3+dfsg-1_all bug

NAME

       gmt.conf - Configuration for GMT

DESCRIPTION

       The  following is a list of the parameters that are user-definable in GMT. The parameter names are always
       given in UPPER CASE. The parameter  values  are  case-insensitive  unless  otherwise  noted.  The  system
       defaults are given in brackets [ for SI (and US) ]. Those marked * can be set on the command line as well
       (the corresponding option is given in parentheses). Note that default distances  and  lengths  below  are
       given   in  both  cm  or  inch;  the  chosen  default  depends  on  your  choice  of  default  unit  (see
       PROJ_LENGTH_UNIT). You can explicitly specify the unit used for distances  and  lengths  by  appending  c
       (cm),  i (inch), or p (points). When no unit is indicated the value will be assumed to be in the unit set
       by PROJ_LENGTH_UNIT. Several parameters take only true or false. Finally, most of these parameters can be
       changed on-the-fly via the --PARAMETER=VALUE option to any GMT program. However, a few are static and are
       only read via the gmt.conf file; these are labeled (static).

COMMON SPECIFICATIONS

       The full explanation for how to specify pens, pattern fills, colors, and fonts can be found  in  the  gmt
       man page.

                                       ┌─────────────────────────────┬─────────┐
                                       │THEMATIC SUB-SECTIONS        │ prefix  │
                                       ├─────────────────────────────┼─────────┤
                                       │COLOR ParametersCOLOR_  │
                                       ├─────────────────────────────┼─────────┤
                                       │DIR ParametersDIR_    │
                                       ├─────────────────────────────┼─────────┤
                                       │FONT ParametersFONT_   │
                                       ├─────────────────────────────┼─────────┤
                                       │FORMAT ParametersFORMAT_ │
                                       ├─────────────────────────────┼─────────┤
                                       │GMT Miscellaneous ParametersGMT_    │
                                       ├─────────────────────────────┼─────────┤
                                       │I/O ParametersIO_     │
                                       ├─────────────────────────────┼─────────┤
                                       │MAP ParametersMAP_    │
                                       ├─────────────────────────────┼─────────┤
                                       │Projection ParametersPROJ_   │
                                       ├─────────────────────────────┼─────────┤
                                       │PostScript ParametersPS_     │
                                       ├─────────────────────────────┼─────────┤
                                       │Calendar/Time ParametersTIME_   │
                                       └─────────────────────────────┴─────────┘

       COLOR_BACKGROUND
              Color used for the background of images (i.e., when z < lowest color table entry) [black].

       COLOR_FOREGROUND
              Color used for the foreground of images (i.e., when z > highest color table entry) [white].

       COLOR_HSV_MAX_S
              Maximum saturation (0-1) assigned for most positive intensity value [0.1].

       COLOR_HSV_MIN_S
              Minimum saturation (0-1) assigned for most negative intensity value [1.0].

       COLOR_HSV_MAX_V
              Maximum value (0-1) assigned for most positive intensity value [1.0].

       COLOR_HSV_MIN_V
              Minimum value (0-1) assigned for most negative intensity value [0.3].

       COLOR_MODEL
              Selects  in which color space a CPT should be interpolated.  By default, color interpolation takes
              place directly on the RGB values which can produce some  unexpected  hues,  whereas  interpolation
              directly  on  the  HSV  values  better  preserves  those hues. The choices are: none (default: use
              whatever the COLOR_MODEL setting in the CPT demands), rgb (force interpolation in RGB), hsv (force
              interpolation in HSV), cmyk (assumes colors are in CMYK but interpolates in RGB).

       COLOR_NAN
              Color used for the non-defined areas of images (i.e., where z == NaN) [127.5].

       DIR_CACHE
              Cache  directory  where  to  save  files downloaded when using external URL addresses or the files
              called earth_relief_res.grd or filenames starting in @ (e.g., @hotspots.txt)

       DIR_DATA
              Session data dir. Overrides the value of the  environment  variable  $GMT_DATADIR  (see  Directory
              parameters in the CookBook).

       DIR_DCW
              Path to optional Digital Chart of the World polygon files.

       DIR_GSHHG
              Path to GSHHG files. Defaults to $GMT_SHAREDIR/coast if empty.

       FONT   Sets  the  default  for  all fonts, except FONT_LOGO. This setting is not included in the gmt.conf
              file.

       FONT_ANNOT
              Sets both FONT_ANNOT_PRIMARY and FONT_ANNOT_SECONDARY to the value specified.  This setting is not
              included in the gmt.conf file.

       FONT_ANNOT_PRIMARY
              Font  used  for primary annotations, etc. [12p,Helvetica,black]. When + is prepended, scale fonts,
              offsets and tick-lengths relative to FONT_ANNOT_PRIMARY.

       FONT_ANNOT_SECONDARY
              Font to use for time axis secondary annotations [14p,Helvetica,black].

       FONT_LABEL
              Font to use when plotting labels below axes [16p,Helvetica,black].

       FONT_LOGO
              Font to use for text plotted as part of the GMT time logo [8p,Helvetica,black].

       FONT_TITLE
              Font to use when plotting titles over graphs [24p,Helvetica,black].

       FORMAT_CLOCK_IN
              Formatting template that indicates how an input clock string is formatted. This template  is  then
              used  to  guide  the  reading  of clock strings in data fields. To properly decode 12-hour clocks,
              append am or pm (or upper case) to match your data records. As examples,  try  hh:mm,  hh:mm:ssAM,
              etc. [hh:mm:ss].

       FORMAT_CLOCK_MAP
              Formatting  template  that indicates how an output clock string is to be plotted. This template is
              then used to guide the formatting of clock strings in plot annotations. See  FORMAT_CLOCK_OUT  for
              details. [hh:mm:ss].

       FORMAT_CLOCK_OUT
              Formatting template that indicates how an output clock string is to be formatted. This template is
              then used to guide the writing of clock strings in data fields. To use a floating point format for
              the  smallest  unit  (e.g.,  seconds),  append  .xxx,  where the number of x indicates the desired
              precision. If no floating point is indicated then the smallest specified unit will be rounded  off
              to  nearest  integer.  For 12-hour clocks, append am, AM, a.m., or A.M. (GMT will replace a|A with
              p|P for pm). If your template starts with a leading hyphen (-) then each integer item (y,m,d) will
              be  printed  without  leading  zeros  (default  uses fixed width formats). As examples, try hh:mm,
              hh.mm.ss, hh:mm:ss.xxxx, hha.m., etc.  [hh:mm:ss]. If the format is simply  -  then  no  clock  is
              output and the ISO T divider between date and clock is omitted.

       FORMAT_DATE_IN
              Formatting  template  that  indicates how an input date string is formatted. This template is then
              used to guide the reading of date strings  in  data  fields.  You  may  specify  either  Gregorian
              calendar  format  or ISO week calendar format. Gregorian calendar: Use any combination of yyyy (or
              yy for 2-digit years; if so see TIME_Y2K_OFFSET_YEAR), mm (or o for abbreviated month name in  the
              current  time language), and dd, with or without delimiters. For day-of-year data, use jjj instead
              of mm and/or dd. Examples can be ddmmyyyy, yy-mm-dd, dd-o-yyyy,  yyyy/dd/mm,  yyyy-jjj,  etc.  ISO
              Calendar:  Expected  template  is  yyyy[-]W[-]ww[-]d,  where ww is ISO week and d is ISO week day.
              Either template must be consistent, e.g., you cannot specify months if you do not  specify  years.
              Examples are yyyyWwwd, yyyy-Www, etc. [yyyy-mm-dd].

       FORMAT_DATE_MAP
              Formatting  template  that  indicates how an output date string is to be plotted. This template is
              then used to guide the plotting of date strings in data fields. See FORMAT_DATE_OUT  for  details.
              In  addition, you may use a single o instead of mm (to plot month name) and u instead of W[-]ww to
              plot  “Week  ##”.  Both  of  these  text  strings  will   be   affected   by   the   GMT_LANGUAGE,
              FORMAT_TIME_PRIMARY_MAP and FORMAT_TIME_SECONDARY_MAP setting. [yyyy-mm-dd].

       FORMAT_DATE_OUT
              Formatting  template that indicates how an output date string is to be formatted. This template is
              then used to guide the writing of date strings in data fields. You may  specify  either  Gregorian
              calendar  format  or ISO week calendar format. Gregorian calendar: Use any combination of yyyy (or
              yy for 2-digit years; if so see TIME_Y2K_OFFSET_YEAR), mm (or o for abbreviated month name in  the
              current  time language), and dd, with or without delimiters. For day-of-year data, use jjj instead
              of mm and/or dd. As examples,  try  yy/mm/dd,  yyyy=jjj,  dd-o-yyyy,  dd-mm-yy,  yy-mm,  etc.  ISO
              Calendar:  Expected  template  is  yyyy[-]W[-]ww[-]d,  where ww is ISO week and d is ISO week day.
              Either template must be consistent, e.g., you cannot specify months if you do not  specify  years.
              As  examples,  try yyyyWww, yy-W-ww-d, etc. If your template starts with a leading hyphen (-) then
              each integer item (y,m,d) will be printed without leading zeros (default uses fixed width formats)
              [yyyy-mm-dd].  If the format is simply - then no date is output and the ISO T divider between date
              and clock is omitted.

       FORMAT_GEO_MAP
              Formatting template that indicates how an output geographical coordinate is to  be  plotted.  This
              template  is  then  used  to  guide  the  plotting of geographical coordinates in data fields. See
              FORMAT_GEO_OUT for details. In addition, you can append A which plots the absolute  value  of  the
              coordinate.  The  default  is  ddd:mm:ss.  Not  all  items  may  be plotted as this depends on the
              annotation interval.

       FORMAT_GEO_OUT
              Formatting template that indicates how an output geographical coordinate is to be formatted.  This
              template  is  then  used  to  guide  the  writing  of geographical coordinates in data fields. The
              template is in general of the form [+|-]D or [+|-]ddd[:mm[:ss]][.xxx][F].  By default,  longitudes
              will be reported in the range [-180,180]. The various terms have the following purpose:

              +D Output longitude in the range [0,360]

              -D Output longitude in the range [-360,0]

              D Use FORMAT_FLOAT_OUT for floating point degrees.

              ddd Fixed format integer degrees

              : delimiter used

              mm Fixed format integer arc minutes

              ss Fixed format integer arc seconds

              .xxx Floating fraction of previous integer field, fixed width.

              F Encode sign using WESN suffix

              G Same as F but with a leading space before suffix

              The default is D.

       FORMAT_FLOAT_MAP
              Format (C language printf syntax) to be used when plotting double precision floating point numbers
              along plot frames and contours.  For geographic coordinates, see FORMAT_GEO_MAP. [%.12lg].

       FORMAT_FLOAT_OUT
              Format (C language printf syntax) to be used when printing double precision floating point numbers
              to  output files. For geographic coordinates, see FORMAT_GEO_OUT. [%.12lg]. To give some columns a
              separate format, supply one or more comma-separated cols:format specifications, where cols can  be
              specific  columns  (e.g.,  5  for 6th since 0 is the first) or a range of columns (e.g., 3-7). The
              last specification without column information will override the  format  for  all  other  columns.
              Alternatively, you can list N space-separated formats and these apply to the first N columns.

       FORMAT_TIME_MAP
              Sets  both  FORMAT_TIME_PRIMARY_MAP  and  FORMAT_TIME_SECONDARY_MAP  to the value specified.  This
              setting is not included in the gmt.conf file.

       FORMAT_TIME_PRIMARY_MAP
              Controls how  primary  month-,  week-,  and  weekday-names  are  formatted.   Choose  among  full,
              abbreviated,  and  character.  If  the leading f, a, or c are replaced with F, A, and C the entire
              annotation will be in upper case [full].

       FORMAT_TIME_SECONDARY_MAP
              Controls how secondary  month-,  week-,  and  weekday-names  are  formatted.  Choose  among  full,
              abbreviated,  and  character.  If  the leading f, a, or c are replaced with F, A, and C the entire
              annotation will be in upper case [full].

       FORMAT_TIME_STAMP
              Defines the format of the time information in the UNIX time stamp.  This format is parsed by the C
              function  strftime,  so  that  virtually  any  text  can  be  used  (even  not containing any time
              information) [%Y %b %d %H:%M:%S].

       GMT_COMPATIBILITY
              Determines if this GMT version should be able to parse command-line  options  for  a  prior  major
              release.   Specify  either  4  or  5.  If  4 is set we will parse obsolete GMT 4 options and issue
              warnings; if 5 is set then parsing GMT 4 only syntax will result in errors [4].

       GMT_EXPORT_TYPE
              This setting is only used by external interfaces  and  controls  the  data  type  used  for  table
              entries.  Choose from double, single, [u]long, [u]int, [u]short, and [u]char [double].

       GMT_EXTRAPOLATE_VAL
              Determines  what  to  do if extrapolating beyond the data domain.  Choose among ‘NaN’, ‘extrap’ or
              ‘extrapval,val’ (without quotes). In the first case return NaN  for  any  element  of  x  that  is
              outside range [Default]. Second case lets the selected algorithm compute the extrapolation values.
              Third case sets the extrapolation values to the constant value passed in ‘val’  (this  value  must
              off course be numeric).

       GMT_CUSTOM_LIBS
              Comma-separated  list  of  GMT-compliant  shared  libraries that extend the capability of GMT with
              additional custom modules [none]. Alternatively, provide a directory name, that MUST  end  with  a
              slash  (or back slash), to use all shared libraries in that directory. On Windows, if the dir name
              is made up only of a single slash (‘/’) search inside a subdirectory called ‘gmt_plugins’  of  the
              directory that contains the ‘gmt’ executable.  See the API documentation for how to build your own
              shared modules.

       GMT_FFT
              Determines which Fast Fourier Transform (FFT) should be used among those that have been configured
              during  installation.  Choose  from  auto  (pick  the  most  suitable for the task among available
              algorithms), fftw[,planner_flag] (The Fastest Fourier Transform in the West), accelerate (Use  the
              Accelerate Framework under OS X; Note, that the number of samples to be processed must be a base 2
              exponent), kiss, (Kiss FFT), brenner Brenner Legacy FFT [auto].  FFTW can “learn” how to optimally
              compute  Fourier transforms on the current hardware and OS by computing several FFTs and measuring
              their execution time. This so gained “Wisdom” will  be  stored  in  and  reloaded  from  the  file
              fftw_wisdom_<hostname>  in  $GMT_USERDIR  or,  if  $GMT_USERDIR  is  not  writable, in the current
              directory. To use this feature append planner_flag, which can be  one  of  measure,  patient,  and
              exhaustive;  see FFTW reference for details. The default FFTW planner flag is estimate, i.e., pick
              a (probably sub-optimal) plan quickly. Note: if you need a single transform of a given size  only,
              the  one-time  cost  of  the smart planner becomes significant. In that case, stick to the default
              planner, estimate, based on heuristics.

       GMT_HISTORY
              Passes the history of past common command options via the gmt.history file. The  different  values
              for  this  setting  are:  true, readonly, false, to either read and write to the gmt.history file,
              only read, or not use the file at all [true].

       GMT_INTERPOLANT
              Determines if linear (linear),  Akima’s  spline  (akima),  natural  cubic  spline  (cubic)  or  no
              interpolation (none) should be used for 1-D interpolations in various programs [akima].

       GMT_LANGUAGE
              Language  to use when plotting calendar and map items such as months and days, map annotations and
              cardinal points. Select from:

              • CN1 Simplified Chinese

              • CN2 Traditional Chinese

              • DE German

              • DK Danish

              • EH Basque

              • ES Spanish

              • FI Finnish

              • FR French

              • GR Greek

              • HI Hawaiian

              • HU Hungarian

              • IE Irish

              • IL Hebrew

              • IS Icelandic

              • IT Italian

              • JP Japanese

              • KR Korean

              • NL Dutch

              • NO Norwegian

              • PL Polish

              • PT Portuguese

              • RU Russian

              • SE Swedish

              • SG Scottish Gaelic

              • TO Tongan

              • TR Turkish

              • UK British English

              • US US English

              If your language is not supported,  please  examine  the  $GMT_SHAREDIR/localization/gmt_us.locale
              file  and  make  a  similar  file.  Please submit it to the GMT Developers for official inclusion.
              Custom language files can be placed in directories  $GMT_SHAREDIR/localization  or  ~/.gmt.  Note:
              Some of these languages may require you to also change the PS_CHAR_ENCODING setting.

       GMT_TRIANGULATE
              Determines   if  we  use  the  Watson  [Default]  or  Shewchuk  algorithm  (if  configured  during
              installation) for triangulation.  Note that Shewchuk is required for operations involving  Voronoi
              constructions.

       GMT_VERBOSE
              (-V)  Determines  the  level  of verbosity used by GMT programs. Choose among 6 levels; each level
              adds to the verbosity of the lower levels: quiet, nnormal  (errors  and  warnings),  compatibility
              warnings, verbose progress reports, long verbose progress reports, debugging messages [c].

       IO_COL_SEPARATOR
              This  setting  determines  what  character will separate ASCII output data columns written by GMT.
              Choose from tab, space, comma, and none [tab].

       IO_GRIDFILE_FORMAT
              Default file format for  grids,  with  optional  scale,  offset  and  invalid  value,  written  as
              ff[+sscale][+ooffset][+ninvalid].  The  2-letter format indicator can be one of [abcegnrs][bsifd].
              See grdconvert and Section grid-file-format of the GMT Technical Reference and Cookbook  for  more
              information.   You may the scale as a for auto-adjusting the scale and/or offset of packed integer
              grids (=ID+sa is a shorthand for =ID+sa+oa).  When invalid is omitted the  appropriate  value  for
              the given format is used (NaN or largest negative). [nf].

       IO_GRIDFILE_SHORTHAND
              If  true,  all  grid  file  names  are  examined  to  see if they use the file extension shorthand
              discussed in Section grid-file-format of the GMT Technical Reference and Cookbook.  If  false,  no
              filename expansion is done [false].

       IO_HEADER
              (-h) Specifies whether input/output ASCII files have header record(s) or not [false].

       IO_LONLAT_TOGGLE
              (-:)  Set if the first two columns of input and output files contain (latitude,longitude) or (y,x)
              rather than the expected (longitude,latitude) or (x,y). false means we have (x,y)  both  on  input
              and  output.  true  means  both  input and output should be (y,x).  IN means only input has (y,x),
              while OUT means only output should be (y,x). [false].

       IO_N_HEADER_RECS
              Specifies how many header records to expect if -h is used [0].  Note: This will skip the specified
              number of records regardless of what they are.  Since any records starting with # is automatically
              considered a header you will only specify a non-zero number in order to skip headers that  do  not
              conform to that convention.

       IO_NAN_RECORDS
              Determines  what  happens  when input records containing NaNs for x or y (and in some cases z) are
              read. Choose between skip, which will simply report how many bad records were  skipped,  and  pass
              [Default],  which  will pass these records on to the calling programs. For most programs this will
              result in output records with NaNs as well, but some will interpret these NaN records to  indicate
              gaps in a series; programs may then use that information to detect segmentation (if applicable).

       IO_NC4_CHUNK_SIZE
              Sets  the  default  chunk  size  for the lat and lon dimension of the z variable. Very large chunk
              sizes and sizes smaller than 128 should be avoided because  they  can  lead  to  unexpectedly  bad
              performance.  Note  that  a  chunk of a single precision floating point variable of size 2896x2896
              completely fills the chunk cache of 32MiB. Specify the chunk size for each dimension separated  by
              a   comma,   or   auto   for  optimally  chosen  chunk  sizes  in  the  range  [128,256).  Setting
              IO_NC4_CHUNK_SIZE will produce netCDF version 4 files, which can only be read with  the  netCDF  4
              library,  unless  all  dimensions  are  less  than 128 or classic is specified for classic netCDF.
              [auto]

       IO_NC4_DEFLATION_LEVEL
              Sets the compression level for netCDF4 files upon output. Values allowed are integers from  0  (no
              compression) to 9 (maximum compression). Enabling a low compression level can dramatically improve
              performance and reduce the size of certain data. While higher compression  levels  further  reduce
              the  data  size, they do so at the cost of extra processing time. This parameter does not apply to
              classic netCDF files. [3]

       IO_SEGMENT_BINARY
              Determines how binary data records with all values set to NaN are interpreted.  Such  records  are
              considered  to be encoded segment headers in binary files provided the number of columns equals or
              exceeds the current setting of IO_SEGMENT_BINARY [2].   Specify  0  or  “off”  to  deactivate  the
              segment header determination.

       IO_SEGMENT_MARKER
              This  holds the character we expect to indicate a segment header in an incoming ASCII data or text
              table [>]. If this marker should be different for output then append  another  character  for  the
              output segment marker. The two characters must be separated by a comma. Two marker characters have
              special meaning: B means “blank line” and will treat blank lines  as  initiating  a  new  segment,
              whereas  N means “NaN record” and will treat records with all NaNs as initiating a new segment. If
              you choose B or N for the output marker then the normal GMT segment header is replaced by a  blank
              or  NaN  record,  respectively,  and  no  segment  header information is written. To use B or N as
              regular segment markers you must escape them with a leading backslash.

       MAP_ANNOT_MIN_ANGLE
              If the angle between the map boundary and the annotation baseline is less than this minimum  value
              (in degrees), the annotation is not plotted (this may occur for certain oblique projections.) Give
              a value in the range [0,90]. [20]

       MAP_ANNOT_MIN_SPACING
              If an annotation would be plotted less than this minimum distance from its closest  neighbor,  the
              annotation is not plotted (this may occur for certain oblique projections.) [0p]

       MAP_ANNOT_OBLIQUE
              This integer is a sum of 6 bit flags (most of which only are relevant for oblique projections): If
              bit 1 is set (1), annotations will occur wherever a gridline  crosses  the  map  boundaries,  else
              longitudes  will  be  annotated  on  the  lower  and  upper boundaries only, and latitudes will be
              annotated on the left and right boundaries only. If bit 2 is set (2), then  longitude  annotations
              will  be  plotted  horizontally.  If  bit  3 is set (4), then latitude annotations will be plotted
              horizontally. If bit 4 is set (8), then oblique tick-marks are extended to give a projection equal
              to  the specified tick length. If bit 5 is set (16), tick-marks will be drawn normal to the border
              regardless of gridline angle. If bit 6 is set (32), then  latitude  annotations  will  be  plotted
              parallel to the border. To set a combination of these, add up the values in parentheses. [1].

       MAP_ANNOT_OFFSET
              Sets  both  MAP_ANNOT_OFFSET_PRIMARY  and MAP_ANNOT_OFFSET_SECONDARY to the value specified.  This
              setting is not included in the gmt.conf file.

       MAP_ANNOT_OFFSET_PRIMARY
              Distance from end of tick-mark to start of annotation [5p].

       MAP_ANNOT_OFFSET_SECONDARY
              Distance from base of primary annotation to the top of the secondary annotation [5p] (Only applies
              to time axes with both primary and secondary annotations).

       MAP_ANNOT_ORTHO
              Determines  which axes will get their annotations (for linear projections) plotted orthogonally to
              the axes. Combine any w, e, s, n, z (uppercase allowed as well). [we] (if nothing specified).

       MAP_DEFAULT_PEN
              Sets the default of all pens related to -W options.  Prepend  +  to  overrule  the  color  of  the
              parameters  MAP_GRID_PEN_PRIMARY, MAP_GRID_PEN_SECONDARY, MAP_FRAME_PEN, MAP_TICK_PEN_PRIMARY, and
              MAP_TICK_PEN_SECONDARY by the color of MAP_DEFAULT_PEN [default,black].

       MAP_DEGREE_SYMBOL
              Determines what symbol is used to plot the degree symbol on  geographic  map  annotations.  Choose
              between ring, degree, colon, or none [ring].

       MAP_FRAME_AXES
              Sets  which  axes  to  draw and annotate. Combine any uppercase W, E, S, N, Z to draw and annotate
              west, east, south, north and/or vertical (perspective view only) axis. Use lower case to draw  the
              axis only, but not annotate. Add an optional + to draw a cube of axes in perspective view. [WESN].

       MAP_FRAME_PEN
              Pen attributes used to draw plain map frame [thicker,black].

       MAP_FRAME_TYPE
              Choose  between  inside,  plain and fancy (thick boundary, alternating black/white frame; append +
              for rounded corners) [fancy]. For some map projections (e.g., Oblique Mercator), plain is the only
              option  even  if  fancy  is set as default. In general, fancy only applies to situations where the
              projected x and y directions parallel the longitude and  latitude  directions  (e.g.,  rectangular
              projections,  polar  projections). For situations where all boundary ticks and annotations must be
              inside the maps (e.g., for preparing geotiffs), chose inside.  Finally, for  Cartesian  plots  you
              can  also  choose  graph,  which  adds a vector to the end of each axis.  This works best when you
              reduce the number of axes plotted.

       MAP_FRAME_WIDTH
              Width (> 0) of map borders for fancy map frame [5p].

       MAP_GRID_CROSS_SIZE
              Sets both MAP_GRID_CROSS_SIZE_PRIMARY and MAP_GRID_CROSS_SIZE_SECONDARY to  the  value  specified.
              This setting is not included in the gmt.conf file.

       MAP_GRID_CROSS_SIZE_PRIMARY
              Size  (>=  0)  of  grid  cross at lon-lat intersections. 0 means draw continuous gridlines instead
              [0p].

       MAP_GRID_CROSS_SIZE_SECONDARY
              Size (>= 0) of grid cross at secondary lon-lat intersections. 0 means  draw  continuous  gridlines
              instead [0p].

       MAP_GRID_CROSS_PEN
              Sets  both  MAP_GRID_CROSS_PEN_PRIMARY  and  MAP_GRID_CROSS_PEN_SECONDARY  to the value specified.
              This setting is not included in the gmt.conf file.

       MAP_GRID_PEN_PRIMARY
              Pen attributes used to draw primary grid lines in dpi units or points (append p) [default,black].

       MAP_GRID_PEN_SECONDARY
              Pen  attributes  used  to  draw  secondary  grid  lines  in  dpi  units  or  points   (append   p)
              [thinner,black].

       MAP_LABEL_OFFSET
              Distance from base of axis annotations to the top of the axis label [8p].

       MAP_LINE_STEP
              Determines  the  maximum  length  (>  0) of individual straight line-segments when drawing arcuate
              lines [0.75p]

       MAP_LOGO
              (-U) Specifies if a GMT logo with system timestamp should be plotted at the lower left  corner  of
              the plot [false].

       MAP_LOGO_POS
              (-U)  Sets  the  justification  and the position of the logo/timestamp box relative to the current
              plots lower left corner of the plot [BL/-54p/-54p].

       MAP_ORIGIN_X
              (-X) Sets the x-coordinate of the origin on the paper for a new plot [1i].  For  an  overlay,  the
              default offset is 0.

       MAP_ORIGIN_Y
              (-Y)  Sets  the  y-coordinate  of the origin on the paper for a new plot [1i]. For an overlay, the
              default offset is 0.

       MAP_POLAR_CAP
              Controls the appearance of gridlines near the poles for all azimuthal projections and a few others
              in  which  the  geographic  poles  are plotted as points (Lambert Conic, Oblique Mercator, Hammer,
              Mollweide, Sinusoidal and van der Grinten). Specify either none (in which case there is no special
              handling)  or  pc_lat/pc_dlon. In that case, normal gridlines are only drawn between the latitudes
              -pc_lat/+*pc_lat*, and above those latitudes the gridlines are spaced at the (presumably  coarser)
              pc_dlon  interval;  the  two  domains are separated by a small circle drawn at the pc_lat latitude
              [85/90]. Note for r-theta (polar) projection where r = 0 is at the center of the plot the  meaning
              of  the  cap is reversed, i.e., the default 85/90 will draw a r = 5 radius circle at the center of
              the map with less frequent radial lines there.

       MAP_SCALE_HEIGHT
              Sets the height (> 0) on the map of the map scale bars drawn by various programs [5p].

       MAP_TICK_LENGTH
              Sets both MAP_TICK_LENGTH_PRIMARY and MAP_TICK_LENGTH_SECONDARY  to  the  value  specified.   This
              setting is not included in the gmt.conf file.

       MAP_TICK_LENGTH_PRIMARY
              The  length  of  a  primary  major/minor tick-marks [5p/2.5p]. If only the first value is set, the
              second is assumed to be 50% of the first.

       MAP_TICK_LENGTH_SECONDARY
              The length of a secondary major/minor tick-marks [15p/3.75p]. If only the first value is set,  the
              second is assumed to be 25% of the first.

       MAP_TICK_PEN
              Sets both MAP_TICK_PEN_PRIMARY and MAP_TICK_PEN_SECONDARY to the value specified.  This setting is
              not included in the gmt.conf file.

       MAP_TICK_PEN_PRIMARY
              Pen  attributes  to  be  used  for  primary  tick-marks  in  dpi  units  or  points   (append   p)
              [thinner,black].

       MAP_TICK_PEN_SECONDARY
              Pen  attributes  to  be  used  for  secondary  tick-marks  in  dpi  units  or  points  (append  p)
              [thinner,black].

       MAP_TITLE_OFFSET
              Distance from top of axis annotations (or axis label, if present) to base of plot title [14p].

       MAP_VECTOR_SHAPE
              Determines the shape of the head of a vector. Normally (i.e., for vector_shape = 0), the head will
              be  triangular,  but  can be changed to an arrow (1) or an open V (2).  Intermediate settings give
              something in between. Negative values (up to -2) are allowed as well [0].

       PROJ_AUX_LATITUDE
              Only applies when geodesics are approximated by great circle distances on  an  equivalent  sphere.
              Select  from authalic, geocentric, conformal, meridional, parametric, or none [authalic]. When not
              none we convert any latitude used in the great circle calculation to the chosen auxiliary latitude
              before doing the distance calculation. See also PROJ_MEAN_RADIUS.

       PROJ_ELLIPSOID
              The (case sensitive) name of the ellipsoid used for the map projections [WGS-84]. Choose among:

         Airy: Applies to Great Britain (1830)
         Airy-Ireland: Applies to Ireland in 1965 (1830)
         Andrae: Applies to Denmark and Iceland (1876)
         APL4.9: Appl. Physics (1965)
         ATS77: Average Terrestrial System, Canada Maritime provinces (1977)
         Australian: Applies to Australia (1965)
         Bessel: Applies to Central Europe, Chile, Indonesia (1841)
         Bessel-Namibia: Same as Bessel-Schwazeck (1841)
         Bessel-NGO1948: Modified Bessel for NGO 1948 (1841)
         Bessel-Schwazeck: Applies to Namibia (1841)
         Clarke-1858: Clarke’s early ellipsoid (1858)
         Clarke-1866: Applies to North America, the Philippines (1866)
         Clarke-1866-Michigan: Modified Clarke-1866 for Michigan (1866)
         Clarke-1880: Applies to most of Africa, France (1880)
         Clarke-1880-Arc1950: Modified Clarke-1880 for Arc 1950 (1880)
         Clarke-1880-IGN: Modified Clarke-1880 for IGN (1880)
         Clarke-1880-Jamaica: Modified Clarke-1880 for Jamaica (1880)
         Clarke-1880-Merchich: Modified Clarke-1880 for Merchich (1880)
         Clarke-1880-Palestine: Modified Clarke-1880 for Palestine (1880)
         CPM: Comm. des Poids et Mesures, France (1799)
         Delambre: Applies to Belgium (1810)
         Engelis: Goddard Earth Models (1985)
         Everest-1830: India, Burma, Pakistan, Afghanistan, Thailand (1830)
         Everest-1830-Kalianpur: Modified Everest for Kalianpur (1956) (1830)
         Everest-1830-Kertau: Modified Everest for Kertau, Malaysia & Singapore (1830)
         Everest-1830-Pakistan: Modified Everest for Pakistan (1830)
         Everest-1830-Timbalai: Modified Everest for Timbalai, Sabah Sarawak (1830)
         Fischer-1960: Used by NASA for Mercury program (1960)
         Fischer-1960-SouthAsia: Same as Modified-Fischer-1960 (1960)
         Fischer-1968: Used by NASA for Mercury program (1968)
         FlatEarth: As Sphere, but implies fast “Flat Earth” distance calculations (1984)
         GRS-67: International Geodetic Reference System (1967)
         GRS-80: International Geodetic Reference System (1980)
         Hayford-1909: Same as the International 1924 (1909)
         Helmert-1906: Applies to Egypt (1906)
         Hough: Applies to the Marshall Islands (1960)
         Hughes-1980: Hughes Aircraft Company for DMSP SSM/I grid products (1980)
         IAG-75: International Association of Geodesy (1975)
         Indonesian: Applies to Indonesia (1974)
         International-1924: Worldwide use (1924)
         International-1967: Worldwide use (1967)
         Kaula: From satellite tracking (1961)
         Krassovsky: Used in the (now former) Soviet Union (1940)
         Lerch: For geoid modeling (1979)
         Maupertius: Really old ellipsoid used in France (1738)
         Mercury-1960: Same as Fischer-1960 (1960)
         MERIT-83: United States Naval Observatory (1983)
         Modified-Airy: Same as Airy-Ireland (1830)
         Modified-Fischer-1960: Applies to Singapore (1960)
         Modified-Mercury-1968: Same as Fischer-1968 (1968)
         NWL-10D: Naval Weapons Lab (Same as WGS-72) (1972)
         NWL-9D: Naval Weapons Lab (Same as WGS-66) (1966)
         OSU86F: Ohio State University (1986)
         OSU91A: Ohio State University (1991)
         Plessis: Old ellipsoid used in France (1817)
         SGS-85: Soviet Geodetic System (1985)
         South-American: Applies to South America (1969)
         Sphere: The mean radius in WGS-84 (for spherical/plate tectonics applications) (1984)
         Struve: Friedrich Georg Wilhelm Struve (1860)
         TOPEX: Used commonly for altimetry (1990)
         Walbeck: First least squares solution by Finnish astronomer (1819)
         War-Office: Developed by G. T. McCaw (1926)
         WGS-60: World Geodetic System (1960)
         WGS-66: World Geodetic System (1966)
         WGS-72: World Geodetic System (1972)
         WGS-84: World Geodetic System [Default] (1984)
         Moon: Moon (IAU2000) (2000)
         Mercury: Mercury (IAU2000) (2000)
         Venus: Venus (IAU2000) (2000)
         Mars: Mars (IAU2000) (2000)
         Jupiter: Jupiter (IAU2000) (2000)
         Saturn: Saturn (IAU2000) (2000)
         Uranus: Uranus (IAU2000) (2000)
         Neptune: Neptune (IAU2000) (2000)
         Pluto: Pluto (IAU2000) (2000)

          Note  that for some global projections, GMT may use a spherical approximation of the ellipsoid chosen,
          setting the flattening to zero, and using a mean radius. A warning will be given when this happens. If
          a  different  ellipsoid name than those mentioned here is given, GMT will attempt to parse the name to
          extract the semi-major axis (a in m) and the flattening. Formats allowed are:

          a implies a zero flattening

          a,inv_f where inv_f is the inverse flattening

          a,b=b where b is the semi-minor axis (in m)

          a,f=f where f is the flattening

          This way a custom ellipsoid (e.g., those used for other  planets)  may  be  used.  Further  note  that
          coordinate transformations in mapproject can also specify specific datums; see the mapproject man page
          for further details and how to view ellipsoid and datum parameters.

       PROJ_GEODESIC
              Selects the algorithm to use for geodesic calculations. Choose between Vincenty [Default],  Rudoe,
              or  Andoyer.  The Andoyer algorithm is only approximate (to within a few tens of meters) but is up
              to 5 times faster.  The Rudoe is given for legacy purposes.  The default Vincenty is  accurate  to
              about 0.5 mm.

       PROJ_LENGTH_UNIT
              Sets  the  unit length. Choose between cm, inch, or point [c (or i)]. Note that, in GMT, one point
              is defined as 1/72 inch (the PostScript definition), while it is often defined as 1/72.27 inch  in
              the typesetting industry. There is no universal definition.

       PROJ_MEAN_RADIUS
              Applies  when geodesics are approximated by great circle distances on an equivalent sphere or when
              surface areas are computed. Select from mean (R_1), authalic (R_2), volumetric (R_3),  meridional,
              or quadratic [authalic].

       PROJ_SCALE_FACTOR
              Changes  the default map scale factor used for the Polar Stereographic [0.9996], UTM [0.9996], and
              Transverse Mercator [1]  projections  in  order  to  minimize  areal  distortion.  Provide  a  new
              scale-factor or leave as default.

       PS_CHAR_ENCODING
              (static)  Names  the  eight  bit  character  set  being used for text in files and in command line
              parameters. This allows GMT to ensure that the PostScript output generates the correct  characters
              on  the  plot.. Choose from Standard, Standard+, ISOLatin1, ISOLatin1+, and ISO-8859-x (where x is
              in the ranges [1,10] or [13,15]). See Appendix F for details [ISOLatin1+ (or Standard+)].

       PS_COLOR_MODEL
              Determines whether PostScript output should use RGB, HSV, CMYK,  or  GRAY  when  specifying  color
              [rgb].  Note  if  HSV  is  selected  it does not apply to images which in that case uses RGB. When
              selecting GRAY, all colors will be converted to gray scale using YIQ (television) conversion.

       PS_COMMENTS
              (static) If true we will issue  comments  in  the  PostScript  file  that  explain  the  logic  of
              operations.  These are useful if you need to edit the file and make changes; otherwise you can set
              it to false which yields a somewhat slimmer PostScript file [false].

       PS_IMAGE_COMPRESS
              Determines if PostScript images  are  compressed  using  the  Run-Length  Encoding  scheme  (rle),
              Lempel-Ziv-Welch  compression  (lzw),  DEFLATE compression (deflate[,level]), or not at all (none)
              [deflate,5]. When specifying deflate, the compression level (1–9) may optionally be appended.

       PS_LINE_CAP
              Determines how the ends of a line segment will be drawn. Choose among a butt cap  (default)  where
              there  is  no  projection  beyond  the  end of the path, a round cap where a semicircular arc with
              diameter equal to the line-width is drawn around the end points,  and  square  cap  where  a  half
              square of size equal to the line-width extends beyond the end of the path [butt].

       PS_LINE_JOIN
              Determines what happens at kinks in line segments. Choose among a miter join where the outer edges
              of the strokes for the two segments are extended until they meet at an  angle  (as  in  a  picture
              frame;  if  the  angle  is  too  acute,  a  bevel  join  is  used  instead,  with threshold set by
              PS_MITER_LIMIT), round join where a circular arc is used to fill in the cracks at the  kinks,  and
              bevel join which is a miter join that is cut off so kinks are triangular in shape [miter].

       PS_MEDIA
              Sets  the  physical format of the current plot paper [a4 (or letter)].  The following formats (and
              their widths and heights in points)  are  recognized  (Additional  site-specific  formats  may  be
              specified  in  the  gmt_custom_media.conf  file in $GMT_SHAREDIR/conf or ~/.gmt; see that file for
              details):

              Media width height

              • A0 2380 3368

              • A1 1684 2380

              • A2 1190 1684

              • A3 842 1190

              • A4 595 842

              • A5 421 595

              • A6 297 421

              • A7 210 297

              • A8 148 210

              • A9 105 148

              • A10 74 105

              • B0 2836 4008

              • B1 2004 2836

              • B2 1418 2004

              • B3 1002 1418

              • B4 709 1002

              • B5 501 709

              • archA 648 864

              • archB 864 1296

              • archC 1296 1728

              • archD 1728 2592

              • archE 2592 3456

              • flsa 612 936

              • halfletter 396 612

              • statement 396 612

              • note 540 720

              • letter 612 792

              • legal 612 1008

              • 11x17 792 1224

              • tabloid 792 1224

              • ledger 1224 792

              For a completely custom format (e.g., for large format plotters) you may also specify WxH, where W
              and H are in points unless you append a unit to each dimension (c, i, m or p [Default]).

       PS_MITER_LIMIT
              Sets  the  threshold angle in degrees (integer in range [0,180]) used for mitered joins only. When
              the angle between joining line segments is smaller than the threshold the corner will be  bevelled
              instead  of mitered. The default threshold is 35 degrees. Setting the threshold angle to 0 implies
              the PostScript default of about 11 degrees.  Setting the threshold angle to 180 causes  all  joins
              to be beveled.

       PS_PAGE_COLOR
              Sets the color of the imaging background, i.e., the paper [white].

       PS_PAGE_ORIENTATION
              (* -P) Sets the orientation of the page. Choose portrait or landscape [landscape].

       PS_SCALE_X
              Global  x-scale  (>  0) to apply to plot-coordinates before plotting.  Normally used to shrink the
              entire output down to fit a specific height/width [1.0].

       PS_SCALE_Y
              Global y-scale (> 0) to apply to plot-coordinates before plotting.  Normally used  to  shrink  the
              entire output down to fit a specific height/width [1.0].

       PS_TRANSPARENCY
              Sets  the  transparency  mode  to  use  when preparing PS for rendering to PDF. Choose from Color,
              ColorBurn,  ColorDodge,  Darken,  Difference,  Exclusion,  HardLight,  Hue,  Lighten,  Luminosity,
              Multiply, Normal, Overlay, Saturation, SoftLight, and Screen [Normal].

       TIME_EPOCH
              Specifies  the  value  of the calendar and clock at the origin (zero point) of relative time units
              (see  TIME_UNIT).  It  is  a   string   of   the   form   yyyy-mm-ddT[hh:mm:ss]   (Gregorian)   or
              yyyy-Www-ddT[hh:mm:ss] (ISO) Default is 1970-01-01T00:00:00, the origin of the UNIX time epoch.

       TIME_INTERVAL_FRACTION
              Determines  if partial intervals at the start and end of an axis should be annotated. If the range
              of the partial interval exceeds the specified fraction of the normal interval stride we will place
              the annotation centered on the partial interval [0.5].

       TIME_IS_INTERVAL
              Used  when  input  calendar  data  should  be truncated and adjusted to the middle of the relevant
              interval. In the following discussion, the unit u can be one of  these  time  units:  (y  year,  o
              month,  u  ISO  week, d day, h hour, m minute, and s second). TIME_IS_INTERVAL can have any of the
              following three values: (1) OFF [Default]. No adjustment, time  is  decoded  as  given.  (2)  +nu.
              Activate  interval  adjustment  for input by truncate to previous whole number of n units and then
              center time on the following interval. (3) -nu. Same, but center time on  the  previous  interval.
              For example, with TIME_IS_INTERVAL = +1o, an input data string like 1999-12 will be interpreted to
              mean 1999-12-15T12:00:00.0 (exactly middle of December), while if TIME_IS_INTERVAL = off then that
              date is interpreted to mean 1999-12-01T00:00:00.0 (start of December) [off].

       TIME_REPORT
              Controls  if  a  time-stamp  should  be  issued  at  start  of all progress reports.  Choose among
              TIMER_CLOCK (absolute time stamp), TIMER_ELAPSED (time since  start  of  session),  or  TIMER_NONE
              [Default].

       TIME_SYSTEM
              Shorthand  for a combination of TIME_EPOCH and TIME_UNIT, specifying which time epoch the relative
              time refers to and what the units are. Choose from one of the  preset  systems  below  (epoch  and
              units are indicated):

              JD -4713-11-25T12:00:00 d (Julian Date)

              MJD 1858-11-17T00:00:00 d (Modified Julian Date)

              J2000 2000-01-01T12:00:00 d (Astronomical time)

              S1985 1985-01-01T00:00:00 s (Altimetric time)

              UNIX 1970-01-01T00:00:00 s (UNIX time)

              RD0001 0001-01-01T00:00:00 s

              RATA 0000-12-31T00:00:00 d

              This  parameter  is  not stored in the gmt.conf file but is translated to the respective values of
              TIME_EPOCH and TIME_UNIT.

       TIME_UNIT
              Specifies the units of relative time data since epoch (see TIME_EPOCH). Choose y (year  -  assumes
              all  years are 365.2425 days), o (month - assumes all months are of equal length y/12), d (day), h
              (hour), m (minute), or s (second) [s].

       TIME_WEEK_START
              When weeks are indicated on time axes, this parameter determines the first day  of  the  week  for
              Gregorian  calendars.  (The  ISO  weekly  calendar  always  begins weeks with Monday.) [Monday (or
              Sunday)].

       TIME_Y2K_OFFSET_YEAR
              When  2-digit  years  are  used  to  represent   4-digit   years   (see   various   FORMAT_DATEs),
              TIME_Y2K_OFFSET_YEAR   gives   the   first   year   in   a  100-year  sequence.  For  example,  if
              TIME_Y2K_OFFSET_YEAR is 1729, then numbers 29 through 99 correspond to 1729  through  1799,  while
              numbers 00 through 28 correspond to 1800 through 1828. [1950].

SEE ALSO

       gmt , gmtdefaults , gmtcolors , gmtget , gmtset

       2018, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe