grdview - Create 3-D perspective grayshaded/colored image or mesh from
a 2-D grd file
grdview relief_file -Jparameters [ -Btickinfo ] [-Ccptfile] [
-Eview_az/view_el ] [ -Gdrapefile] [ -Iintensfile] [ -K ] [ -L[flags] ]
[ -Nlevel[/r/g/b]] [ -O ] [ -P ] [ -Qtype ] [
-Rwest/east/south/north/zmin/zmax[r] ] [ -Ssmooth ] [
-U[/dx/dy/][label] ] [ -V ] [ -Wtype/pen ] [ -Xx-shift ] [ -Yy-shift ]
[ -Zzlevel ] [ -ccopies ]
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.
2-D gridded data set to be imaged (the relief of the surface).
-J Selects the map projection. Scale is inch/degree, 1:xxxxx, or
width in inch (upper case modifier).
-Jmscale (Mercator - Greenwich and Equator as origin)
-Jmlon0/lat0/scale (Mercator - Give meridian and standard
-Joalon0/lat0/azimuth/scale (Oblique Mercator - point and
-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)
-Juzone/scale (UTM - Universal Transverse Mercator)
-Jylon0/lats/scale (Basic Cylindrical Projection)
-Jslon0/lat0/scale (General Stereographic)
-Jklon0/scale (Eckert VI)
-Jrlon0/scale (Winkel Tripel)
-Jpscale (Linear projection for polar (theta,r) coordinates)
-Jxx-scale[l|ppow][/y-scale[l|ppow]] (Linear, log, and power
More details can be found in the psbasemap manpages.
-Jz Sets the vertical scaling (for 3-D maps). Same syntax as -Jx.
No space between the option flag and the associated arguments.
-B Sets map boundary tickmark intervals. See psbasemap for 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).
-E Sets the view point by specifying azimuth and elevation in
degrees. [Default is 180/90]
-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].
-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 r/g/b is
provided, the frontal facade between the plane and the data
perimeter is colored.
-O Selects Overlay plot mode [Default initializes a new plot
-P Selects Portrait plotting mode [GMT Default is Landscape, see
gmtdefaults to change this].
-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. 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 . 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
-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 in inch [Default is (-0.75i/-
0.75i)]. Optionally, append a label, or c (which will plot the
-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 = 3, color
= 0/0/0, texture = solid].
-Wm Sets the pen attributes used for the mesh. [Default: width = 1,
color = 0/0/0, texture = solid]. You must also select -Qm or
-Qsm for meshlines to be drawn.
Shift origin of plot by (x-shift,y-shift) inch [Default is
(a1i,a1i) for new plots, (0,0) for overlays]. Prepend a for
absolute coordinates; the default (r) will reset plot origin.
-Z Sets the z-level of the basemap .
-c Specifies the number of plot copies. [Default is 1]
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 0.5 inch/degree along the standard parallels 18 and 24, with
vertical scale 50 mgal/inch, and looking at the surface from SW at 30
degree elevation, try
grdview hawaii_grav.grd -Jl18/24/0.5i -Chawaii.cpt -Jz0.02i -Qm -N-100
-E225/30 -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 inch/x-unit and tickmarks every 5 units, with intensities
provided by the file intens.grd, and looking from the SE, try
grdview image.grd -Jx10.0i -Ccolor.rgb -Qs -E135/30 -Iintens.grd >
To make the same plot using the rastering option with dpi = 50, try
grdview image.grd -Jx10.0i -Ccolor.rgb -Qi50 -E135/30 -Iintens.grd >
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, try
grdview topography.grd -JM6i -Gmagnetics.grd -Cmag_intens.cpt -Qs
-E140/30 -Itopo_intens.grd > draped3D.ps
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 bilinear or bicubic 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.
gmt, grdcontour, grdimage, nearneighbor, psbasemap, pscontour, pstext,
Man(1) output converted with