pscontour
pscontour - Contour xyz-data by direct triangulation
SYNOPSIS
pscontour xyzfile -Ccptfile -Jparameters
-Rwest/east/south/north[r] [ -A[-][ffont_size][aan
gle][/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] ]
DESCRIPTION
pscontour reads an ASCII [or binary] xyz-file and produces
a raw contour plot by triangulation. By default, the opti
mal Delaunay triangulation is performed (using either She
whuck's [1996]' or Watson's [1982] method as selected dur
ing GMT installation), but the user' may optionally pro
vide a second file with network information, such as a
triangular mesh used for finite element modeling. In addi
tion 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 con
toured.
-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 ano
tated.
-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 MEA
SURE_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 ori
gin)
-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)
-Jtlon0/scale (TM - Transverse Mercator, with Equa
tor 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 man
pages.
-R west, east, south, and north specify the Region of
interest. To specify boundaries in degrees and min
utes [and seconds], use the dd:mm[:ss] format.
Append r if lower left and upper right map coordi
nates are given instead of wesn.
OPTIONS
No space between the option flag and the associated argu
ments.
-A Several anotation formatting options can be set to
modify the form of the annotation. Give - to dis
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 multi
segment file is created instead.
-E Sets the view point by specifying azimuth and ele
vation 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 .gmt
defaults 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 spec
ified pen attributes [Default is no mesh].
-M When used in conjunction with -D a single multiseg
ment 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).
-O Selects Overlay plot mode [Default initializes a
new plot system].
-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
-U Draw Unix System time stamp on plot. User may spec
ify 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 appear
ance; 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 (lati
tude,longitude) input/output. [Default is (longi
tude,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 preci
sion [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 temper
ature 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
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(l), grdcontour(l), grdimage(l), nearneighbor(l),
psbasemap(l), psscale(l), surface(l), triangulate(l)
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
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