Provided by: gmt-manpages_3.4.4-1_all bug


       gmtselect - Select data subsets based on multiple spatial criteria


       gmtselect  [  infiles  ]  [  -Amin_area[/min_level/max_level]  ]  [  -C[f]dist/ptfile  ] [
       -Dresolution ] [  -Fpolygonfile  ]  [  -H[nrec]  ]  [  -I[cflrs]  ]  [  -Jparameters  ]  [
       -L[dist/linefile] ] [ -M[flag] ] [ -Nmaskvalues[o] ] [ -Rwest/east/south/north[r] ] [ -V ]
       [ -: ] [ -bi[s][n] ] [ -bo[s][n] ]


       gmtselect is a filter that reads (longitude, latitude) positions from the first 2  columns
       of  infiles  [or  standard input] and uses a combination of 1-5 criteria to pass or reject
       the records. Records can be selected based  on  whether  or  not  they  are  1)  inside  a
       rectangular region (-R [and -J]), 2) within dist km of any point in ptfile, 3) within dist
       km of any line in linefile, 4) inside one of the  polygons  in  the  polygonfile,  and  5)
       inside  geographical  features  (based  on  coastlines).   The  sense  of the tests can be
       reversed for each of these 5 criteria by using the -I option.  See option  -:  on  how  to
       read (latitude,longitude) files.
               No  space between the option flag and the associated arguments. Use upper case for
       the option flags and lower case for modifiers.

              ASCII (or binary, see-b) data file(s) to be operated on.  If  not  given,  standard
              input is read.


       -A     Ignored  unless -N is set. Geographical features with an area smaller than min_area
              in km^2 or of hierarchical level that  is  lower  than  min_level  or  higher  than
              max_level will be ignored [Default is 0/4 (all features)]. See DATABASE INFORMATION
              in the pscoast man-pages for more details.

       -C     Pass all records whose location is within dist km of any of the points  in  ptfile.
              If  dist  is  zero  then the 3rd column of ptfile must have each point's individual
              radius of influence.  Prepend f  to  indicate  you  want  approximate  flat'  earth
              distance calculations (faster) than exact great circle calculations (slower).

       -D     Ignored  unless  -N is set. Selects the resolution of the coastline data set to use
              ((f)ull, (h)igh, (i)ntermediate, (l)ow, or (c)rude). The resolution  drops  off  by
              ~80%  between data sets. [Default is l]. Note that because the coastlines differ in
              details is not guaranteed that a point will  remain  inside  [or  outside]  when  a
              different resolution is selected.

       -F     Pass  all  records  whose  location  is  within  one  of the closed polygons in the
              multiple-segment file polygonfile.

       -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     Reverses the sense of the test for each of the criteria specified:
                      c select records NOT inside any point's circle of influence.'
                      f select records NOT inside any of the polygons.
                      l select records NOT within the specified distance of any line.
                      r select records NOT inside the specified rectangular region.
                      s select records NOT considered inside as specified by -A, -D, -N.

       -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.


              -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)


              -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)


              -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)


              -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.

       -L     Pass  all  records  whose location is within dist km of any of the line segments in
              the multiple-segment file linefile. If dist is zero then the  2nd  column  of  each
              sub-header  in the ptfile must have each lines's individual distance value.'  If no
              arguments are given, it means instead that the x column contains longitudes,  which
              may  differ from the region in -R by [multiples of] 360 degrees [Default assumes no

       -M     Multiple segment file. Segments are separated by a record whose first character  is
              flag.  [Default is '>'].

       -N     Pass all records whose location is inside specified geographical features.  Specify
              if records should be skipped or kkept using 1 of 2 formats:
              Append o to let points exactly on feature  boundaries  be  considered  outside  the
              feature  [Default  is  inside]. [Default is s/k/s/k/s (i.e., s/k), which passes all
              points on dry land].

       -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.   If  no  map
              projection is supplied we implicitly set -Jx1.

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

       -:     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 2 input columns].

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


       To extract the subset of data set that is within 300 km of any of the points in pts.d  but
       more than 100 km away from the lines in lines.d, try

       gmtselect lonlatfile -Jd1d -C300/pts.d -L100/lines.d -Il > subset

       Here,  you  must specify a mapprojection so that knows you are giving it geographical data
       (otherwise 300 would be interpreted as Cartesian distance in x-y units instead of km).  To
       keep  all  points  in  data.d  except  those on land, as determined by the high-resolution
       coastlines, try

       gmtselect data.d -R120/121/22/24 -Dh -Ns/k > subset


       gmtdefaults(1gmt), gmt(1gmt), grdlandmask(1gmt), pscoast(1gmt)

                                            1 Jan 2004                               GMTSELECT(l)