xenial (1) gmtinfo.1gmt.gz

Provided by: gmt-common_5.2.1+dfsg-3build1_all bug

NAME

       gmtinfo - Return information about data tables

SYNOPSIS

       gmtinfo  [  table  ]  [  a|f|s ] [  ] [ [dx[/dy]] ] [ L|l|H|hcol ] [ [p|f|s]dx[/dy[/dz...] ] [ [x][y] ] [
       dz[/col] ] [ [level] ] [ -bi<binary> ] [ -di<nodata> ] [ -f<flags> ] [  -g<gaps>  ]  [  -h<headers>  ]  [
       -i<flags> ] [ -o<flags> ] [ -r ] [ -:[i|o] ]

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

DESCRIPTION

       gmtinfo  reads its standard input [or from files] and finds the extreme values in each of the columns. It
       recognizes NaNs and will print warnings if the number of columns  vary  from  record  to  record.  As  an
       option,  gmtinfo  will find the extent of the first n columns rounded up and down to the nearest multiple
       of the supplied increments. By default, this output will be in the  form  -Rw/e/s/n  which  can  be  used
       directly  in the command line for other programs (hence only dx and dy are needed), or the output will be
       in column form for as many columns as there are increments provided. A similar option (-T) will provide a
       -Tzmin/zmax/dz string for makecpt.

REQUIRED ARGUMENTS

       None.

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.

       -Aa|f|s
              Specify how the range should be reported. Choose -Aa for the range of all files combined,  -Af  to
              report  the  range  for  each  file  separately,  and -As to report the range for each segment (in
              multisegment files) separately. [Default is -Aa].

       -C     Report the min/max values per column in separate columns [Default  uses  <min/max>  format].  When
              used, users may also use -o to limit which output columns should be reported [all].

       -D     Modifies  results  obtained  by  -I  by shifting the region to better align with the center of the
              data.  Optionally, append granularity for this shift [Default performs an exact shift].

       -EL|l|H|hcol
              Returns the record whose column col contains the minimum (l) or  maximum  (h)  value.  Upper  case
              (L|H)  works  on absolute value of the data. In case of multiple matches, only the first record is
              returned. If col is not specified we default to the last column in the data.

       -I[p|f|s]dx[/dy[/dz...]
              Report the min/max of the first n columns to the  nearest  multiple  of  the  provided  increments
              (separate  the  n  increments  by slashes), and output results in the form -Rw/e/s/n (unless -C is
              set). If only one increment is given  we  also  use  it  for  the  second  column  (for  backwards
              compatibility).  To  override this behavior, use -Ipdx. If the input x- and y-coordinates all have
              the same phase shift relative to the dx and dy increments  then  we  use  those  phase  shifts  in
              determining   the   region,   and   you  may  use  -r  to  switch  from  gridline-registration  to
              pixel-registration.  For irregular data both phase shifts are set to 0 and the -r is ignored.  Use
              -Ifdx[/dy]  to  report an extended region optimized to give grid dimensions for fastest results in
              programs using FFTs.  Use  -Isdx[/dy]  to  report  an  extended  region  optimized  to  give  grid
              dimensions  for  fastest  results  in  programs like surface.  If dx is given as - then the actual
              min/max of the input is given in the -R string.

       -S[x][y]
              Add extra space for error bars. Useful together with -I option and when later plotting  with  psxy
              -E.  -Sx  leaves  space for horizontal error bars using the values in third (2) column. -Sy leaves
              space for vertical error bars using the values in third (2) column. -S or -Sxy  leaves  space  for
              both error bars using the values in third and fourth (2 and 3) columns.

       -Tdz[/col]
              Report the min/max of the first (0'th) column to the nearest multiple of dz and output this in the
              form -Tzmin/zmax/dz.  To use another column, append /col. Only works when -I is selected.

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

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

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

       -f[i|o]colinfo (more ...)
              Specify data types of input and/or output columns.

       -g[a]x|y|d|X|Y|D|[col]z[+|-]gap[u] (more ...)
              Determine data gaps and line breaks.

       -h[i|o][n][+c][+d][+rremark][+rtitle] (more ...)
              Skip or produce header record(s).

       -icols[l][sscale][ooffset][,...] (more ...)
              Select input columns (0 is first column).

       -ocols[,...] (more ...)
              Select output columns (0 is first column).

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

       -:[i|o] (more ...)
              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 use just -).

       -+ or just +
              Print an extensive usage (help) message, including the explanation 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 options, then exits.

       --version
              Print GMT version and exit.

       --show-datadir
              Print full path to GMT share directory and exit.

ASCII FORMAT PRECISION

       The  ASCII output formats of numerical data are controlled by parameters in your gmt.conf file. Longitude
       and latitude are formatted according to FORMAT_GEO_OUT, whereas other values are formatted  according  to
       FORMAT_FLOAT_OUT.  Be  aware that the format in effect can lead to loss of precision in the output, which
       can lead to various problems downstream. If you find the output is not  written  with  enough  precision,
       consider   switching   to   binary  output  (-bo  if  available)  or  specify  more  decimals  using  the
       FORMAT_FLOAT_OUT setting.

EXAMPLES

       To find the extreme values in the file ship_gravity.xygd:

              gmt info ship_gravity.xygd

       Output should look like

              ship_gravity.xygd: N = 6992 <326.125/334.684> <-28.0711/-8.6837> <-47.7/177.6> <0.6/3544.9>

       To find the extreme values in the file track.xy to the nearest 5 units but shifted to within  1  unit  of
       the data center, and use this region to draw a line using psxy, run

              gmt psxy `gmt info -I5 -D1 track.xy` track.xy -Jx1 -B5 -P > track.ps

       To  find  the min and max values for each of the first 4 columns, but rounded to integers, and return the
       result individually for each data file, use

              gmt info profile_*.txt -C -I1/1/1/1

BUGS

       The -I option does not yet work properly  with  time  series  data  (e.g.,  -f0T).  Thus,  such  variable
       intervals as months and years are not calculated. Instead, specify your interval in the same units as the
       current setting of TIME_UNIT.

SEE ALSO

       gmt, gmtconvert

       2015, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe