manpagez: man pages & more
man psmask(1)
Home | html | info | man
psmask(1)                             GMT                            psmask(1)




NAME

       psmask - Use data tables to clip or mask map areas with no coverage


SYNOPSIS

       psmask [ table ]
        -Iincrement
        -Jparameters
        -Rregion [  -B[p|s]parameters ] [  -Ddumpfile ] [  -F[l|r] ] [  -Gfill
       ] [  -Jz|Zparameters ] [  -K ] [  -L[+|-]nodegrid ] [  -N ] [  -O  ]  [
       -P  ]  [   -Qcut  ] [  -Ssearch_radius[unit] ] [  -T ] [  -U[stamp] ] [
       -V[level] ] [  -Xx_offset ] [  -Yy_offset ] [ -bibinary ] [ -dinodata ]
       [  -eregexp ] [ -hheaders ] [ -iflags ] [ -pflags ] [ -r ] [ -ttransp ]
       [ -:[i|o] ]

       psmask -C [ -K ] [ -O ]

       Note: No space is allowed between the option flag  and  the  associated
       arguments.


DESCRIPTION

       psmask  reads a (x,y,z) file [or standard input] and uses this informa-
       tion to find out which grid cells are reliable. Only grid  cells  which
       have one or more data points are considered reliable. As an option, you
       may specify a radius of influence. Then, all grid cells that are within
       radius of a data point are considered reliable.  Furthermore, an option
       is provided to reverse the sense of the test.  Having found  the  reli-
       able/not  reliable points, psmask will either paint tiles to mask these
       nodes (with the -T switch), or use contouring to create  polygons  that
       will  clip  out regions of no interest.  When clipping is initiated, it
       will stay in effect until turned off by a second call to  psmask  using
       the -C option.


REQUIRED

       -Ixinc[unit][+e|n][/yinc[unit][+e|n]]
              x_inc  [and  optionally  y_inc] is the grid spacing. Optionally,
              append a suffix modifier.  Geographical  (degrees)  coordinates:
              Append  m  to indicate arc minutes or s to indicate arc seconds.
              If one of the units e, f, k, M, n or u is appended instead,  the
              increment  is assumed to be given in meter, foot, km, Mile, nau-
              tical mile or US survey foot, respectively,  and  will  be  con-
              verted  to  the equivalent degrees longitude at the middle lati-
              tude of the region (the conversion depends  on  PROJ_ELLIPSOID).
              If  y_inc is given but set to 0 it will be reset equal to x_inc;
              otherwise it will be converted to degrees latitude. All  coordi-
              nates:  If +e is appended then the corresponding max x (east) or
              y (north) may be slightly adjusted  to  fit  exactly  the  given
              increment  [by default the increment may be adjusted slightly to
              fit the given domain]. Finally, instead of giving  an  increment
              you  may  specify the number of nodes desired by appending +n to
              the supplied integer argument; the increment  is  then  recalcu-
              lated  from  the  number  of nodes and the domain. The resulting
              increment value depends on whether you  have  selected  a  grid-
              line-registered  or  pixel-registered grid; see App-file-formats
              for details. Note: if -Rgrdfile is used then  the  grid  spacing
              has already been initialized; use -I to override the values.

       -Jparameters (more a|)
              Select map projection. [Not mandatory when -D].

       -Rxmin/xmax/ymin/ymax[+r][+uunit] (more a|)
              Specify the region of interest.

       For perspective view p, optionally append /zmin/zmax. (more a|)


OPTIONAL ARGUMENTS

       table  One  or  more ASCII (or binary, see -bi[ncols][type]) data table
              file(s) holding a number of data columns. If no tables are given
              then we read from standard input.

       -B[p|s]parameters (more a|)
              Set map boundary frame and axes attributes.

       -C     Mark end of existing clip path. No input file is needed. Implic-
              itly sets -O. Also supply -X and -Y settings if you  have  moved
              since the clip started.

       -Ddumpfile
              Dump  the  (x,y)  coordinates of each clipping polygon to one or
              more output files (or stdout if template is not given). No plot-
              ting  will  take place. If template contains the C-format speci-
              fier %d (including modifications like %05d) then  polygons  will
              be  written to different files; otherwise all polygons are writ-
              ten to the specified file (template). The files are ASCII unless
              -bo  is  used.  See -Q to exclude small polygons from considera-
              tion.

       -F[l|r]
              Force clip contours (polygons)  to  be  oriented  so  that  data
              points are to the left (-Fl [Default]) or right (-Fr) as we move
              along the perimeter [Default is arbitrary orientation]. Requires
              -D.

       -Gfill Paint the clip polygons (or tiles) with a selected fill [Default
              is no fill].

       -Jz|Zparameters (more a|)
              Set z-axis scaling; same syntax as -Jx.

       -K (more a|)
              Do not finalize the PostScript plot.

       -L[+|-]nodegrid
              Save the internal grid with ones (data constraint) and zeros (no
              data)  to the named nodegrid [no grid saved].  Use L+ to convert
              the no data flags to NaNs before writing the grid, while L- will
              instead convert the data flags to NaNs.

       -N     Invert  the sense of the test, i.e., clip regions where there is
              data coverage.

       -O (more a|)
              Append to existing PostScript plot.

       -P (more a|)
              Select aPortraita plot orientation.

       -Q     Do not dump polygons with less than cut number of points  [Dumps
              all polygons]. Only applicable if -D has been specified.

       -Ssearch_radius[unit]
              Sets  radius  of  influence.  Grid nodes within radius of a data
              point are considered reliable. [Default is 0, which  means  that
              only grid cells with data in them are reliable]. Append the dis-
              tance unit (see UNITS).

       -T     Plot tiles instead of clip polygons. Use -G to set tile color or
              pattern. Cannot be used with -D.

       -U[[just]/dx/dy/][c|label] (more a|)
              Draw GMT time stamp logo on plot.

       -V[level] (more a|)
              Select verbosity level [c].

       -X[a|c|f|r][x-shift[u]]

       -Y[a|c|f|r][y-shift[u]] (more a|)
              Shift plot origin.

       -bi[ncols][t] (more a|)
              Select native binary input. [Default is 2 input columns].

       -dinodata (more a|)
              Replace input columns that equal nodata with NaN.

       -e[~]^<i>apattern^<i>a | -e[~]/regexp/[i] (more a|)
              Only accept data records that match the given pattern.

       -h[i|o][n][+c][+d][+rremark][+rtitle] (more a|)
              Skip or produce header record(s). Not used with binary data.

       -icols[+l][+sscale][+ooffset][,^<i>a|] (more a|)
              Select input columns and transformations (0 is first column).

       -p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more a|)
              Select perspective view.

       -r (more a|)
              Set pixel node registration [gridline].

       -t[transp] (more a|)
              Set PDF transparency level in percent.

       -:[i|o] (more a|)
              Swap 1st and 2nd column on input and/or output.

       -^ or just -
              Print  a  short  message  about  the syntax of the command, then
              exits (NOTE: on Windows just use -).

       -+ or just +
              Print an extensive usage (help) message, including the  explana-
              tion  of  any  module-specific  option  (but  not the GMT common
              options), then exits.

       -? or no arguments
              Print a complete usage (help) message, including the explanation
              of all options, then exits.


UNITS

       For  map distance unit, append unit d for arc degree, m for arc minute,
       and s for arc second, or e for meter [Default], f for foot, k for km, M
       for  statute  mile,  n  for nautical mile, and u for US survey foot. By
       default we compute such distances using a spherical approximation  with
       great  circles.  Prepend - to a distance (or the unit is no distance is
       given) to perform aFlat Eartha calculations (quicker but less accurate)
       or  prepend  +  to perform exact geodesic calculations (slower but more
       accurate).


EXAMPLES

       To make an overlay PostScript file that will mask out the regions of  a
       contour map where there is no control data using clip polygons, use:

              gmt psmask africa_grav.xyg -R20/40/20/40 -I5m -JM10i -O -K > mask.ps

       We  do it again, but this time we wish to save the clipping polygons to
       file all_pols.txt:

              gmt psmask africa_grav.xyg -R20/40/20/40 -I5m -Dall_pols.txt

       A repeat of the first example but this time we use white tiling:

              gmt psmask africa_grav.xyg -R20/40/20/40 -I5m -JM10i -T -O -K -Gwhite > mask.ps


SEE ALSO

       gmt(1), gmtcolors(5), grdmask(1), surface(1), psbasemap(1), psclip(1)


COPYRIGHT

       2017, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe



5.4.2                            Jun 24, 2017                        psmask(1)

gmt5 5.4.2 - Generated Thu Jun 29 15:31:41 CDT 2017
© manpagez.com 2000-2021
Individual documents may contain additional copyright information.