NAME
minmax - Find extreme values in data tables
SYNOPSIS
minmax [ files] [ -C ] [ -D ] [ -H[nrec] ] [ -Idx[/dy] ] [ -L ] [
-M[flag] ] [ -: ] [ -bi[s][n] ]
DESCRIPTION
minmax reads its standard input [or from files] and finds the extreme
values in each of the columns. It recognizes NaNs and will print warn-
ings 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.
xyzfile
ASCII [or binary, see -b] file(s) holding a fixed number of data
columns.
OPTIONS
-C Report the min/max values per column in separate columns
[Default uses <min/max> format]
-D Sets longitude discontinuity to the Dateline (-180/+180)
[Default is Greenwich (0-360)]. Requires -L.
-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 mul-
tiple of dx and dy, and output this in the form -Rw/e/s/n
(unless -C is set).
-L Indicates that the x column contains longitudes, which may be
periodic in 360 degrees [Default assumes no periodicity].
-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)]. Applies to
geographic coordinates only. 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].
EXAMPLES
To find the extreme values in the file ship_gravity.xygd, try
minmax 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
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 inte-
gers, try
minmax junkfile -C -I1
SEE ALSO
gmt(l)
GMT3.4.6 1 Jan 2005 MINMAX(l)
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