minmax - Find extreme values in data tables
minmax [ files] [ -C ] [ -H[nrec] ] [ -Idx[/dy] ] [ -M[flag] ] [ -: ] [
minmax 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, minmax will find the extent of the first two columns rounded
up and down to the nearest multiple of dx/dy. This output will be in
the form -Rw/e/s/n which can be used directly in the command line for
other programs, or simply in column form.
ASCII [or binary, see -b] file(s) holding a fixed number of data
-C Report the min/max values per column in separate columns [Default
uses <min/max> format]
-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 Report the min/max of the first two columns to the nearest
multiple of dx and dy, and output this in the form -Rw/e/s/n
(unless -C is set).
-M Multiple segment file(s). Segments are separated by a special
record. For ASCII files the first character must be flag
[Default is '>']. For binary files all fields must be NaN.
-: Toggles between (longitude,latitude) and (latitude,longitude)
input/output. [Default is (longitude,latitude)]. Only works
when -I is selected.
-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].
To find the extreme values in the file ship_gravity.xygd, try
Output should look like
ship_gravity.xygd: N = 6992 <326.125/334.684> <-28.0711/-8.6837> <-
To find the extreme values in the file track.xy to the nearest 5 units
and use this region to draw a line using psxy, try
psxy `minmax -I5 track.xy` track.xy -Jx1 -B5 -P > track.ps
To find the min and max values for each column, but rounded to
minmax junkfile -C -I1
Man(1) output converted with