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NAME

       pscontour - Contour xyz-data by direct triangulation

SYNOPSIS

       pscontour         xyzfile        -Ccptfile        -Jparameters        -Rwest/east/south/north[r]        [
       -A[-][ffont_size][aangle][/r/g/b][o]] ] [ -Btickinfo ] [ -D[dumpfile] ] [ -Eview_az/view_el ] [ -Ggap ] [
       -H[nrec] ] [ -I ] [ -K ] [ -Lpen ] [ -M[flag] ] [ -N ] [ -O ] [ -P ] [ -Tindexfile ] [ -U[/dx/dy/][label]
       ] [ -V ] [ -W[+]pen ] [ -Xx-shift ] [ -Yy-shift ] [ -ccopies ] [ -: ] [ -bi[s][n] ] [ -bo[s][n] ]

DESCRIPTION

       pscontour reads an ASCII [or binary] xyz-file and produces  a  raw  contour  plot  by  triangulation.  By
       default,  the  optimal  Delaunay  triangulation is performed (using either Shewhuck's [1996]' or Watson's
       [1982] method as selected during GMT installation), but the user' may optionally provide  a  second  file
       with  network  information,  such  as  a triangular mesh used for finite element modeling. In addition to
       contours, the area between contours may be painted according to the color palette file.

       xyzfile
              Raw ASCII (or binary, see -b) xyz data to be contoured.

       -C     name of the color palette file. Must have discrete colors if you want to paint the  surface  (-I).
              Only contours that have anotation flags set will be anotated.

       -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 .gmtdefaults, but this can be
              overridden on the command line by appending the c, i, or m to the scale/width value.

              CYLINDRICAL PROJECTIONS:

              -Jclon0/lat0/scale (Cassini)
              -Jjlon0/scale (Miller)
              -Jmscale (Mercator - Greenwich and Equator as origin)
              -Jmlon0/lat0/scale (Mercator - Give meridian and standard parallel)
              -Joalon0/lat0/azimuth/scale (Oblique Mercator - point and azimuth)
              -Joblon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
              -Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and pole)
              -Jqlon0/scale (Equidistant Cylindrical Projection (Plate Carree))
              -Jtlon0/scale (TM - Transverse Mercator, with Equator as y = 0)
              -Jtlon0/lat0/scale (TM - Transverse Mercator, set origin)
              -Juzone/scale (UTM - Universal Transverse Mercator)
              -Jylon0/lats/scale (Basic Cylindrical Projection)

              AZIMUTHAL PROJECTIONS:

              -Jalon0/lat0/scale (Lambert).
              -Jelon0/lat0/scale (Equidistant).
              -Jflon0/lat0/horizon/scale (Gnomonic).
              -Jglon0/lat0/scale (Orthographic).
              -Jslon0/lat0/[slat/]scale (General Stereographic)

              CONIC PROJECTIONS:

              -Jblon0/lat0/lat1/lat2/scale (Albers)
              -Jdlon0/lat0/lat1/lat2/scale (Equidistant)
              -Jllon0/lat0/lat1/lat2/scale (Lambert)

              MISCELLANEOUS PROJECTIONS:

              -Jhlon0/scale (Hammer)
              -Jilon0/scale (Sinusoidal)
              -Jk[f|s]lon0/scale (Eckert IV (f) and VI (s))
              -Jnlon0/scale (Robinson)
              -Jrlon0/scale (Winkel Tripel)
              -Jvlon0/scale (Van der Grinten)
              -Jwlon0/scale (Mollweide)

              NON-GEOGRAPHICAL PROJECTIONS:

              -Jp[a]scale[/origin] (polar (theta,r) coordinates, optional a for azimuths and offset theta [0])
              -Jxx-scale[l|ppow][/y-scale[l|ppow]] (Linear, log, and power scaling)
              More details can be found in the psbasemap manpages.

       -R     west, east, south, and north specify the Region of interest. To specify boundaries in degrees  and
              minutes  [and  seconds],  use  the  dd:mm[:ss]  format. Append r if lower left and upper right map
              coordinates are given instead of wesn.

OPTIONS

       No space between the option flag and the associated arguments.

       -A     Several anotation formatting options can be set to modify the form of the annotation.  Give  -  to
              disable  all anotations.  Append ffont_size to change font size [9], append /r/g/b to change color
              of text fill box [PAGE_COLOR], append aangle to fix annotation angle  [Default  follows  contour],
              and append o to draw the outline of the surrounding text box [Default is no outline].

       -B     Sets map boundary tickmark intervals. See psbasemap for details.

       -D     Dump  the (x,y,z) coordinates of each contour to separate files, one for each contour segment. The
              files will be named dumpfile_cont_segment[_i].xyz, where cont is the contour value and segment  is
              a  running  segment number for each contour interval (for closed contours we append _i.)  However,
              when -M is used in conjunction with -D a single multisegment file is created instead.

       -E     Sets the view point by specifying azimuth and elevation in degrees. [Default is 180/90]

       -G     gap is distance between each annotation along the same contour [Default is 10c (or 4i)].

       -H     Input file(s) has Header record(s). Number of header  records  can  be  changed  by  editing  your
              .gmtdefaults file. If used, GMT default is 1 header record.

       -I     Color the triangles using the color palette table.

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

       -L     Draw the underlying triangular mesh using the specified pen attributes [Default is no mesh].

       -M     When  used  in conjunction with -D a single multisegment file is created, and each contour section
              is preceeded by a header record whose first column is flag followed by the contour level.

       -N     Do NOT clip contours or image at the boundaries [Defaults will clip to fit inside region -R).

       -bo    Selects binary output. Append s for single precision [Default is double].

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

       -T     Give name of file with network information. Each record must contain triplets of node numbers  for
              a triangle [Default computes these using Delaunay triangulation (see triangulate)].

       -U     Draw  Unix  System  time  stamp on plot. User may specify where the lower left corner of the stamp
              should fall on the page relative to lower left corner of plot. Optionally, append a  label,  or  c
              (which  will  plot the command string.). The GMT parameters UNIX_TIME and UNIX_TIME_POS can affect
              the appearance; see the gmtdefaults man page for details.

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

       -W     Select contouring and set contour pen attributes. If the + flag is set then the contour lines  are
              colored according to the cpt file (see -C).

       -X -Y  Shift  origin  of  plot by (x-shift,y-shift).  Prepend a for absolute coordinates; the default (r)
              will reset plot origin.

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

       -:     Toggles  between  (longitude,latitude)  and   (latitude,longitude)   input/output.   [Default   is
              (longitude,latitude)].  Applies to geographic coordinates only.

       -bi    Selects  binary input. Append s for single precision [Default is double].  Append n for the number
              of columns in the binary file(s).  [Default is 3 input columns].  Use 4-byte integer triplets  for
              node ids (-T).

       -bo    Selects binary output. Append s for single precision [Default is double].

EXAMPLES

       To  make  a raw contour plot from the file topo.xyz and drawing the contours (pen = 2) given in the color
       palette file topo.cpt on a Lambert map at 0.5 inch/degree along the standard parallels 18 and 24, try

       pscontour topo.xyz -R320/330/20/30 -Jl18/24/0.5i -Ctopo.cpt -W0.5p > topo.ps

       To create a color PostScript plot of the numerical temperature solution obtained  on  a  triangular  mesh
       whose  node coordinates and temperatures are stored in temp.xyz and mesh arrangement is given by the file
       mesh.ijk, using the colors in temp.cpt, try

       pscontour temp.xyz -R0/150/0/100 -Jx0.1 -Ctemp.cpt -G -W0.25p > temp.ps

BUGS

       Sometimes there will appear to be thin lines of the wrong color  in  the  image.   This  is  a  round-off
       problem which may be remedied by using a higher value of DOTS_PR_INCH in the .gmtdefaults file.

SEE ALSO

       gmt(1gmt),   grdcontour(1gmt),   grdimage(1gmt),   nearneighbor(1gmt),   psbasemap(1gmt),  psscale(1gmt),
       surface(1gmt), triangulate(1gmt)

REFERENCES

       Watson, D. F., 1982, Acord: Automatic contouring of raw data, Comp. & Geosci., 8, 97-101.
       Shewchuck, J. R., 1996, Triangle: Engineering a 2D Quality  Mesh  Generator  and  Delaunay  Triangulator,
       First Workshop on Applied Computational Geometry (Philadelphia, PA), 124-133, ACM, May 1996.
       www.cs.cmu.edu/~quake/triangle.html

                                                   1 Jan 2004                                       PSCONTOUR(l)