GRDVIEW
Section: Misc. Reference Manual Pages (l)
Updated: DATE
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#ifdef SI
#define UNIT cm
#define LEN_1 1.5
#define LEN_2 20
#define LEN_3 0.05
#define LEN_4 2.5
#define SCALE -Jm2.5
#else
#define UNIT inch
#define LEN_1 0.5
#define LEN_2 50
#define LEN_3 0.02
#define LEN_4 1
#define SCALE -Jm1
#endif
NAME
grdview - Create 3-D perspective grayshaded/colored image or mesh from a 2-D grd file
SYNOPSIS
grdview relief_file -Jparameters
[ -Btickinfo ] [-Ccptfile] [ -Dndec ] [ -Eview_az/view_el ]
[ -Fred/green/blue ] [ -Gdrapefile] [ -Iintensfile] [ -K ]
[ -Mmeshpen] [ -Nlevel[/r/g/b]] [ -O ] [ -P ]
[ -Qtype ] [ -Rwest/east/south/north/zmin/zmax[r] ] [ -Ssmooth ]
[ -U[/dx/dy/][label] ] [ -V ] [ -Wcontourpen ] [ -Xx-shift ]
[ -Yy-shift ] [ -Zzlevel ] [ -ccopies ]
DESCRIPTION
grdview reads a 2-D gridded 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 grd file.
- relief_file
-
2-D gridded data set to be imaged (the relief of the surface).
#include "explain_-j.txt"
#include "explain_-Jz.txt"
OPTIONS
No space between the option flag and the associated arguments.
#include "explain_-b.txt"
- -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).
- -D
-
Sets number of decimals used to specify color/gray in PostScript output. Makes smaller output file
at the expense of less color resolution. E.g., 3 gives 1000, 2 gives 100, and 1 gives 10 choices each
or r, g, and b, values [3].
- -E
-
Sets the view point by specifying azimuth and elevation in degrees. [Default is 180/90]
- -F
-
Sets the color used for Frame and annotation. [Default is black]
- -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.
- -I
-
Gives the name of a grdfile with intensities in the (-1,+1) range. [Default is no illumination].
#include "explain_-K.txt"
- -M
-
Sets the pen attributes used for the mesh. [Default: width = 1, color = 0/0/0, texture = solid]
- -N
-
Draws a plane at this z-level. If the optional r/g/b is provided, the frontal facade between
the plane and the data perimeter is colored.
#include "explain_-O.txt"
#include "explain_-P.txt"
#include "explain_-R.txt"
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.
- -Q
-
Select one of three settings: 1. Specify m for mesh plot [Default], and optionally append /r/g/b 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].
This option will apply a simple clippath to avoid overwriting the background (since the resulting image is rectangular).
Depending on the projection this may backfire; if so turn clipping off by using upper case I.
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.
- -S
-
Smooth the contours before plotting (see grdcontour) [Default is no smoothing]
#include "explain_-U.txt"
#include "explain_-V.txt"
- -W
-
Draw contour lines on top of surface or mesh (not image). Append pen attributes used for the contours.
[Default: width = 3, color = 0/0/0, texture = solid].
#include "explain_-XY.txt"
- -Z
-
Sets the z-level of the basemap [0].
#include "explain_-c.txt"
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 LEN_1 UNIT/degree along the standard parallels 18 and 24, with vertical scale LEN_2 mgal/UNIT, and
looking at the surface from SW at 30 degree elevation, try
grdview hawaii_grav.grd -Jl18/24/LEN_1 -Chawaii.cpt -JzLEN_3 -Qm -N-100 -E225/30 -W > 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 UNIT/x-unit
and tickmarks every 5 units, with intensities provided by the file intens.grd, and looking from the SE, try
grdview image.grd -Jx10.0 -Ccolor.rgb -Qs -E135/30 -Iintens.grd > image3D.ps
To make the same plot using the rastering option with dpi = 50, try
grdview image.grd -Jx10.0 -Ccolor.rgb -Qi50 -E135/30 -Iintens.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 scaling at LEN_4 UNIT/degree
and tickmarks every 1 degree, with intensities provided by the file topo_intens.grd, and looking from the SE, try
grdview topography.grd SCALE -Gmagnetics.grd -Cmag_intens.cpt -Qs -E140/30 -Itopo_intens.grd > draped3D.ps
BUGS
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 grdfile(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 quasi-bilinear continuous color variations within polygons by using scanline conversion to image the polygons. However,
when using -Qi, the -B option is deactivated; plot axes separately as a psbasemap overlay.
Header must be plotted separately using pstext.
SEE ALSO
gmt, grdcontour, grdimage, nearneighbor, psbasemap, pscontour, pstext, surface
#include "refs.i"
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- EXAMPLES
-
- BUGS
-
- SEE ALSO
-
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