Provided by: gmt_4.5.11-1build1_amd64 bug

NAME

       grdview - Create 3-D perspective grayshaded/colored image or mesh from a 2-D grid file

SYNOPSIS

       grdview    relief_file    -Jparameters   [   -B[p|s]parameters   ]   [   -Ccptfile   ]   [
       -Eazim/elev[+wlon/lat[/z]][+vx0/y0] ] [ -Gdrapefile | -Ggrd_r,grd_g,grd_b ] [ -Iintensfile
       ] [ -Jz|Zparameters ] [ -K ] [ -L[flags] ] [ -Nlevel[/color] ] [ -O ] [ -P ] [ -Qtype[g] ]
       [  -Rwest/east/south/north[/zmin/zmax][r]  ]  [   -Ssmooth   ]   [   -T[s][o[pen]]   ]   [
       -U[just/dx/dy/][c|label]  ] [ -V ] [ -Wtype/pen ] [ -X[a|c|r][x-shift[u]] ] [ -Y[a|c|r][y-
       shift[u]] ] [ -Zzlevel ] [ -ccopies ]

DESCRIPTION

       grdview reads a 2-D grid file and produces a 3-D  perspective  plot  by  drawing  a  mesh,
       painting  a  colored/grayshaded  surface made up of polygons, or by scanline conversion of
       these polygons to a rasterimage.  Options include draping a data set on top of a  surface,
       plotting  of  contours  on  top of the surface, and apply artificial illumination based on
       intensities provided in a separate grid file.

       relief_file
              2-D gridded data set to be imaged (the relief of  the  surface).   (See  GRID  FILE
              FORMAT below.)

       -J     Selects  the map projection. Scale is UNIT/degree, 1:xxxxx, or width in UNIT (upper
              case modifier).  UNIT is cm, inch, or m, depending on the MEASURE_UNIT  setting  in
              .gmtdefaults4, but this can be overridden on the command line by appending c, i, or
              m to the scale/width value.  When central meridian is optional, default  is  center
              of  longitude  range  on -R option.  Default standard parallel is the equator.  For
              map height, max dimension, or min dimension, append  h,  +,  or  -  to  the  width,
              respectively.
              More details can be found in the psbasemap man pages.

              CYLINDRICAL PROJECTIONS:

              -Jclon0/lat0/scale (Cassini)
              -Jcyl_stere/[lon0/[lat0/]]scale (Cylindrical Stereographic)
              -Jj[lon0/]scale (Miller)
              -Jm[lon0/[lat0/]]scale (Mercator)
              -Jmlon0/lat0/scale (Mercator - Give meridian and standard parallel)
              -Jo[a]lon0/lat0/azimuth/scale (Oblique Mercator - point and azimuth)
              -Jo[b]lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
              -Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and pole)
              -Jq[lon0/[lat0/]]scale (Cylindrical Equidistant)
              -Jtlon0/[lat0/]scale (TM - Transverse Mercator)
              -Juzone/scale (UTM - Universal Transverse Mercator)
              -Jy[lon0/[lat0/]]scale (Cylindrical Equal-Area)

              CONIC PROJECTIONS:

              -Jblon0/lat0/lat1/lat2/scale (Albers)
              -Jdlon0/lat0/lat1/lat2/scale (Conic Equidistant)
              -Jllon0/lat0/lat1/lat2/scale (Lambert Conic Conformal)
              -Jpoly/[lon0/[lat0/]]scale ((American) Polyconic)

              AZIMUTHAL PROJECTIONS:

              -Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area)
              -Jelon0/lat0[/horizon]/scale (Azimuthal Equidistant)
              -Jflon0/lat0[/horizon]/scale (Gnomonic)
              -Jglon0/lat0[/horizon]/scale (Orthographic)
              -Jglon0/lat0/altitude/azimuth/tilt/twist/Width/Height/scale (General Perspective).
              -Jslon0/lat0[/horizon]/scale (General Stereographic)

              MISCELLANEOUS PROJECTIONS:

              -Jh[lon0/]scale (Hammer)
              -Ji[lon0/]scale (Sinusoidal)
              -Jkf[lon0/]scale (Eckert IV)
              -Jk[s][lon0/]scale (Eckert VI)
              -Jn[lon0/]scale (Robinson)
              -Jr[lon0/]scale (Winkel Tripel)
              -Jv[lon0/]scale (Van der Grinten)
              -Jw[lon0/]scale (Mollweide)

              NON-GEOGRAPHICAL PROJECTIONS:

              -Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
              -Jxx-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log, and power scaling)

       -Jz    Sets the vertical scaling (for 3-D maps).  Same syntax as -Jx.

OPTIONS

       No space between the option flag and the associated arguments.

       -B     Sets map boundary annotation and tickmark intervals; see the psbasemap man page for
              all the details.

       -C     name of the color palette file.  Must be present if you want  (1)  mesh  plot  with
              contours (-Qm), or (2) shaded/colored perspective image (-Qs or -Qi).  For -Qs: You
              can specify that you want to skip a z-slice by setting red = -; to  use  a  pattern
              give red = P|pdpi/pattern[:Fr/g/b[Br/g/b]].

       -E     Sets  the  viewpoint's  azimuth and elevation (for perspective view) [180/90].  For
              frames used for animation, you may want to append + to fix the center of your  data
              domain  (or  specify a particular world coordinate point with +wlon0/lat[/z]) which
              will project to the center of your page size (or specify  the  coordinates  of  the
              projected view point with +vx0/y0).

       -G     Drape the image in drapefile on top of the relief provided by relief_file. [Default
              is relief_file].  Note that -Jz and -N  always  refers  to  the  relief_file.   The
              drapefile  only  provides  the information pertaining to colors, which is looked-up
              via the cpt file (see -C).  Alternatively,  give  three  grid  files  separated  by
              commas.   These  files  must  contain  the red, green, and blue colors directly (in
              0-255 range) and no cpt file is needed.  The drapefile may be of higher  resolution
              than the relief_file.

       -I     Gives the name of a grid file with intensities in the (-1,+1) range. [Default is no
              illumination].

       -K     More PostScript code will be appended later [Default terminates the plot system].

       -L     Boundary condition flags may be x or y or xy indicating data is periodic  in  range
              of  x  or  y or both, or flags may be g indicating geographical conditions (x and y
              are lon and lat).  [Default uses "natural" conditions  (second  partial  derivative
              normal  to  edge  is  zero).]   If  no  flags are set, use bilinear rather than the
              default bicubic resampling when draping is required.

       -N     Draws a plane at this z-level.  If the optional  color  is  provided,  the  frontal
              facade  between  the  plane and the data perimeter is colored.  See -Wf for setting
              the pen used for the outline.  (See SPECIFYING COLOR below).

       -O     Selects Overlay plot mode [Default initializes a new plot system].

       -P     Selects Portrait plotting mode [Default is Landscape,  see  gmtdefaults  to  change
              this].

       -Q     Select  one  of four settings: 1. Specify m for mesh plot [Default], and optionally
              append /color for a different mesh paint [white].  2. Specify s for  surface  plot,
              and  optionally  append m to have mesh lines drawn on top of surface.  3. Specify i
              for image plot,  and  optionally  append  the  effective  dpi  resolution  for  the
              rasterization  [100].   4. Specify c.  Same as -Qi but will make nodes with z = NaN
              transparent, using the colormasking feature in PostScript Level 3  (the  PS  device
              must  support  PS  Level  3).  For any of these choices, you may force a monochrome
              image by appending g.  Colors are then  converted  to  shades  of  gray  using  the
              (television) YIQ transformation.

       -R     xmin, xmax, ymin, and ymax specify the Region of interest.  For geographic regions,
              these limits correspond to west, east, south, and north and you may specify them in
              decimal  degrees  or in [+-]dd:mm[:ss.xxx][W|E|S|N] format.  Append r if lower left
              and upper right map coordinates are given instead of w/e/s/n.  The  two  shorthands
              -Rg and -Rd stand for global domain (0/360 and -180/+180 in longitude respectively,
              with -90/+90 in latitude).  Alternatively, specify the name  of  an  existing  grid
              file  and  the  -R  settings  (and grid spacing, if applicable) are copied from the
              grid.  For calendar  time  coordinates  you  may  either  give  (a)  relative  time
              (relative  to  the  selected  TIME_EPOCH and in the selected TIME_UNIT; append t to
              -JX|x), or (b) absolute time of the form [date]T[clock] (append T  to  -JX|x).   At
              least  one  of  date and clock must be present; the T is always required.  The date
              string must be of the form [-]yyyy[-mm[-dd]] (Gregorian calendar) or yyyy[-Www[-d]]
              (ISO  week  calendar),  while  the clock string must be of the form hh:mm:ss[.xxx].
              The use of delimiters and their type and positions must  be  exactly  as  indicated
              (however,  input, output and plot formats are customizable; see gmtdefaults).  This
              option may be used to indicate the range used for the 3-D axes [Default  is  region
              given  by  the  relief_file].  You may ask for a larger w/e/s/n region to have more
              room between the image and the axes.   A  smaller  region  than  specified  in  the
              relief_file will result in a subset of the grid.

       -S     Smooth the contours before plotting (see grdcontour) [Default is no smoothing].

       -T     Plot  image without any interpolation.  This involves converting each node-centered
              bin into a polygon which is then painted separately.  Append s to skip nodes with z
              =  NaN.   This  option  is  useful for categorical data where interpolating between
              values is meaningless.  Optionally, append o to draw the tile outlines, and specify
              a  custom  pen if the default pen is not to your liking.  As this option produces a
              flat surface it cannot be combined with -JZ or -Jz.  (See SPECIFYING PENS below).

       -U     Draw Unix System time stamp on plot.  By adding just/dx/dy/, the user  may  specify
              the justification of the stamp and where the stamp should fall on the page relative
              to lower left corner of the plot.  For example, BL/0/0 will align  the  lower  left
              corner  of  the  time  stamp  with  the lower left corner of the plot.  Optionally,
              append a label, or c (which will plot the command  string.).   The  GMT  parameters
              UNIX_TIME,  UNIX_TIME_POS,  and UNIX_TIME_FORMAT can affect the appearance; see the
              gmtdefaults man page for details.  The time string will be in the locale set by the
              environment variable TZ (generally local time).

       -V     Selects  verbose  mode,  which  will  send progress reports to stderr [Default runs
              "silently"].

       -Wc    Draw contour lines on top of surface or mesh (not image).   Append  pen  attributes
              used  for  the contours.  [Default: width = 0.75p, color = black, texture = solid].
              (See SPECIFYING PENS below).

       -Wm    Sets the pen attributes used for the mesh. [Default: width = 0.25p, color =  black,
              texture = solid].  You must also select -Qm or -Qsm for meshlines to be drawn.

       -Wf    Sets  the  pen  attributes  used  for  the facade. [Default: width = 0.25p, color =
              black, texture = solid].  You must also select -N for  the  facade  outline  to  be
              drawn.  (See SPECIFYING PENS below).

       -X -Y  Shift  plot  origin  relative  to  the  current  origin  by  (x-shift,y-shift)  and
              optionally append the length unit (c, i, m, p).  You can prepend  a  to  shift  the
              origin  back  to  the  original position after plotting, or prepend  r [Default] to
              reset the current origin to the new location.  If -O is used then the  default  (x-
              shift,y-shift)   is   (0,0),   otherwise  it  is  (r1i,  r1i)  or  (r2.5c,  r2.5c).
              Alternatively, give c to align the center coordinate (x or y) of the plot with  the
              center of the page based on current page size.

       -Z     Sets the z-level of the basemap [Default is the bottom of the z-axis].

       -c     Specifies the number of plot copies. [Default is 1].

   SPECIFYING PENS
       pen    The  attributes  of  lines  and  symbol  outlines  as  defined  by  pen  is a comma
              delimetered list of width, color and texture, each of which is optional.  width can
              be   indicated   as   a   measure   (points,  centimeters,  inches)  or  as  faint,
              thin[ner|nest], thick[er|est], fat[ter|test], or obese.   color  specifies  a  gray
              shade  or  color  (see SPECIFYING COLOR below).  texture is a combination of dashes
              `-' and dots `.'.

   SPECIFYING COLOR
       color  The color of lines, areas and patterns can be specified by a valid color name; by a
              gray  shade  (in  the  range  0-255); by a decimal color code (r/g/b, each in range
              0-255; h-s-v, ranges 0-360, 0-1, 0-1; or c/m/y/k, each  in  range  0-1);  or  by  a
              hexadecimal  color  code (#rrggbb, as used in HTML).  See the gmtcolors manpage for
              more information and a full list of color names.

GRID FILE FORMATS

       GMT is able to recognize many of the commonly used grid  file  formats,  as  well  as  the
       precision,  scale  and  offset  of the values contained in the grid file. When GMT needs a
       little help with that, you can add the suffix =id[/scale/offset[/nan]], where id is a two-
       letter  identifier of the grid type and precision, and scale and offset are optional scale
       factor and offset to be applied to all grid values, and nan is the value used to  indicate
       missing  data.   See  grdreformat(1)  and  Section 4.17 of the GMT Technical Reference and
       Cookbook for more information.

       When reading a netCDF file that contains multiple grids, GMT will read,  by  default,  the
       first  2-dimensional  grid  that  can  find in that file. To coax GMT into reading another
       multi-dimensional variable in the grid file, append  ?varname  to  the  file  name,  where
       varname  is the name of the variable. Note that you may need to escape the special meaning
       of ? in your shell program by putting a backslash in  front  of  it,  or  by  placing  the
       filename  and suffix between quotes or double quotes.  See grdreformat(1) and Section 4.18
       of the GMT Technical Reference and Cookbook for more information, particularly on  how  to
       read splices of 3-, 4-, or 5-dimensional grids.

EXAMPLES

       To  make  a  mesh plot from the file hawaii_grav.grd and drawing the contours given in the
       color palette file hawaii.cpt on a  Lambert  map  at  1.5  cm/degree  along  the  standard
       parallels 18 and 24, with vertical scale 20 mgal/cm, and looking at the surface from SW at
       30 degree elevation, run

       grdview hawaii_grav.grd -Jl 18/24/1.5c -C hawaii.cpt -Jz 0.05c -Qm -N-100 -E 225/30 -Wc  >
       hawaii_grav_image.ps

       To  create  a  illuminated color perspective plot of the gridded data set image.grd, using
       the color palette file color.rgb, with linear scaling at 10 cm/x-unit and tickmarks  every
       5 units, with intensities provided by the file intens.grd, and looking from the SE, use

       grdview image.grd -Jx 10.0c -C color.rgb -Qs -E 135/30 -I intens.grd  > image3D.ps

       To make the same plot using the rastering option with dpi = 50, use

       grdview image.grd -Jx 10.0c -C color.rgb -Qi 50 -E 135/30 -I intens.grd  > image3D.ps

       To create a color PostScript perspective plot of the gridded data set magnetics.grd, using
       the color  palette  file  mag_intens.cpt,  draped  over  the  relief  given  by  the  file
       topography.grd,  with  Mercator  map  width  of  6 inch and tickmarks every 1 degree, with
       intensities provided by the file topo_intens.grd, and looking from the SE, run

       grdview topography.grd -JM  6i  -G  magnetics.grd  -C  mag_intens.cpt  -Qs  -E  140/30  -I
       topo_intens.grd  > draped3D.ps

       Given topo.grd and the Landsat image veggies.ras, first run gmt2rgb to get the red, green,
       and blue grids, and then drape this image over the topography and  shade  the  result  for
       good measure.  The commands are

       gmt2rgb veggies.ras -G layer_%c.grd
       grdview     topo.grd     -JM     6i     -Qi    -E    140/30    -I    topo_intens.grd    -G
       layer_r.grd,layer_g.grd,layer_b.grd > image.ps

REMARKS

       For the -Qs option:  PostScript provides no  way  of  smoothly  varying  colors  within  a
       polygon,  so  colors  can only vary from polygon to polygon.  To obtain smooth images this
       way you may resample the grid file(s) using grdsample  or  use  a  finer  grid  size  when
       running gridding programs like surface or nearneighbor.  Unfortunately, this produces huge
       PostScript files.  The alternative is to use the -Qi option, which  computes  bilinear  or
       bicubic  continuous color variations within polygons by using scanline conversion to image
       the polygons.

SEE ALSO

       GMT(1),   gmt2rgb(1),   gmtcolors(5),   grdcontour(1),    grdimage(1),    nearneighbor(1),
       psbasemap(1), pscontour(1), pstext(1), surface(1)