NAME
minmax - Find extreme values in data tables
SYNOPSIS
minmax [ files] [ -C ] [ -H[nrec] ] [ -Idx[/dy] ] [ -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 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.
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]
-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].
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 integers, try
minmax junkfile -C -I1
SEE ALSO
gmt(l)