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<title>MINMAX</title>
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<h1 align=center>MINMAX</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#OPTIONS">OPTIONS</a><br>
<a href="#ASCII FORMAT PRECISION">ASCII FORMAT PRECISION</a><br>
<a href="#EXAMPLES">EXAMPLES</a><br>
<a href="#BUGS">BUGS</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<a name="NAME"></a>
<h2>NAME</h2>
<p style="margin-left:11%; margin-top: 1em">minmax −
Find extreme values in data tables</p>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<p style="margin-left:11%; margin-top: 1em"><b>minmax</b> [
<i>files</i>] [ <b>−C</b> ] [
<b>−EL</b>|<b>l</b>|<b>H</b>|<b>h</b><i>col</i> ] [
<b>−H</b>[<b>i</b>][<i>nrec</i>] ] [
<b>−I</b>[<b>p</b>]<i>dx</i>[/<i>dy</i>[/<i>dz</i>...]
] [ <b>−S</b>[<b>x</b>][<b>y</b>] ] [
<b>−T</b><i>dz</i>[/<i>col</i>] ] [
<b>−:</b>[<b>i</b>|<b>o</b>] ] [
<b>−bi</b>[<b>s</b>|<b>S</b>|<b>d</b>|<b>D</b>[<i>ncol</i>]|<b>c</b>[<i>var1</i><b>/</b><i>...</i>]]
] [ <b>−f</b>[<b>i</b>|<b>o</b>]<i>colinfo</i> ] [
<b>−m</b>[<b>i</b>|<b>o</b>][<i>flag</i>] ]</p>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<p style="margin-left:11%; margin-top: 1em"><b>minmax</b>
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, <b>minmax</b> will find the
extent of the first <i>n</i> columns rounded up and down to
the nearest multiple of the supplied increments. By default,
this output will be in the form
<b>−R</b><i>w/e/s/n</i> which can be used directly in
the command line for other programs (hence only <i>dx</i>
and <i>dy</i> are needed), or the output will be in column
form for as many columns as there are increments provided. A
similar option (<b>−T</b>) will provide a
<b>−T</b><i>zmin/zmax/dz</i> string for makecpt.
<i><br>
xyzfile</i></p>
<p style="margin-left:22%;">ASCII [or binary, see
<b>−b</b>] file(s) holding a fixed number of data
columns.</p>
<a name="OPTIONS"></a>
<h2>OPTIONS</h2>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−C</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Report the min/max
values per column in separate columns [Default uses
<min/max> format].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−E</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Returns the record
whose column <i>col</i> contains the minimum (<b>l</b>) or
maximum (<b>h</b>) value. Upper case (<b>L|H</b>) works on
absolute value of the data. In case of multiple matches,
only the first record is returned.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−H</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Input file(s) has
header record(s). If used, the default number of header
records is <b><A HREF="gmtdefaults.html#N_HEADER_RECS">N_HEADER_RECS</A></b>. Use <b>−Hi</b> if
only input data should have header records [Default will
write out header records if the input data have them]. Blank
lines and lines starting with # are always skipped.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−I</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Report the min/max
of the first <i>n</i> columns to the nearest multiple of the
provided increments (separate the <i>n</i> increments by
slashes), and output results in the form
<b>−R</b><i>w/e/s/n</i> (unless <b>−C</b> is
set). If only one increment is given we also use it for the
second column (for backwards compatibility). To override
this behaviour, use <b>−Ip</b><i>dx</i>.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−S</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Add extra space for
error bars. Useful together with <b>−I</b> option and
when later plotting with <b>psxy −E</b>.
<b>−Sx</b> leaves space for horizontal error bars
using the values in third (2) column. <b>−Sy</b>
leaves space for vertical error bars using the values in
third (2) column. <b>−S</b> or <b>−Sxy</b>
leaves space for both error bars using the values in third
and fourth (2 and 3) columns.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−T</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Report the min/max
of the first (0’th) column to the nearest multiple of
<i>dz</i> and output this in the form
<b>−T</b><i>zmin/zmax/dz</i>. To use another column,
append /<i>col</i>.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−:</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Toggles between
(longitude,latitude) and (latitude,longitude) input and/or
output. [Default is (longitude,latitude)]. Append <b>i</b>
to select input only or <b>o</b> to select output only.
[Default affects both]. Only works when <b>−I</b> is
selected.</p> </td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−bi</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Selects binary
input. Append <b>s</b> for single precision [Default is
<b>d</b> (double)]. Uppercase <b>S</b> or <b>D</b> will
force byte-swapping. Optionally, append <i>ncol</i>, the
number of columns in your binary input file if it exceeds
the columns needed by the program. Or append <b>c</b> if the
input file is netCDF. Optionally, append
<i>var1</i><b>/</b><i>var2</i><b>/</b><i>...</i> to specify
the variables to be read. [Default is 2 input columns].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−f</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Special formatting
of input and/or output columns (time or geographical data).
Specify <b>i</b> or <b>o</b> to make this apply only to
input or output [Default applies to both]. Give one or more
columns (or column ranges) separated by commas. Append
<b>T</b> (absolute calendar time), <b>t</b> (relative time
in chosen <b><A HREF="gmtdefaults.html#TIME_UNIT">TIME_UNIT</A></b> since <b><A HREF="gmtdefaults.html#TIME_EPOCH">TIME_EPOCH</A></b>),
<b>x</b> (longitude), <b>y</b> (latitude), or <b>f</b>
(floating point) to each column or column range item.
Shorthand <b>−f</b>[<b>i</b>|<b>o</b>]<b>g</b> means
<b>−f</b>[<b>i</b>|<b>o</b>]0<b>x</b>,1<b>y</b>
(geographic coordinates).</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−m</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Multiple segment
file(s). Segments are separated by a special record. For
ASCII files the first character must be <i>flag</i> [Default
is ’>’]. For binary files all fields must be
NaN and <b>−b</b> must set the number of output
columns explicitly. By default the <b>−m</b> setting
applies to both input and output. Use <b>−mi</b> and
<b>−mo</b> to give separate settings to input and
output.</p> </td>
</table>
<a name="ASCII FORMAT PRECISION"></a>
<h2>ASCII FORMAT PRECISION</h2>
<p style="margin-left:11%; margin-top: 1em">The ASCII
output formats of numerical data are controlled by
parameters in your .gmtdefaults4 file. Longitude and
latitude are formatted according to
<b><A HREF="gmtdefaults.html#OUTPUT_DEGREE_FORMAT">OUTPUT_DEGREE_FORMAT</A></b>, whereas other values are
formatted according to <b><A HREF="gmtdefaults.html#D_FORMAT">D_FORMAT</A></b>. 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 (<b>−bo</b> if
available) or specify more decimals using the
<b><A HREF="gmtdefaults.html#D_FORMAT">D_FORMAT</A></b> setting.</p>
<a name="EXAMPLES"></a>
<h2>EXAMPLES</h2>
<p style="margin-left:11%; margin-top: 1em">To find the
extreme values in the file ship_gravity.xygd:</p>
<p style="margin-left:11%; margin-top: 1em"><b>minmax</b>
ship_gravity.xygd</p>
<p style="margin-left:11%; margin-top: 1em">Output should
look like</p>
<p style="margin-left:11%; margin-top: 1em">ship_gravity.xygd:
N = 6992 <326.125/334.684> <-28.0711/-8.6837>
<-47.7/177.6> <0.6/3544.9></p>
<p style="margin-left:11%; margin-top: 1em">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, run</p>
<p style="margin-left:11%; margin-top: 1em"><b><A HREF="psxy.html">psxy</A></b>
‘<b>minmax −I</b>5 track.xy‘ track.xy
<b>−Jx</b>1 <b>−B</b>5 <b>−P</b> >
track.ps</p>
<p style="margin-left:11%; margin-top: 1em">To find the min
and max values for each of the first 4 columns, but rounded
to integers, use</p>
<p style="margin-left:11%; margin-top: 1em"><b>minmax</b>
junkfile <b>−C −I</b>1/1/1/1</p>
<a name="BUGS"></a>
<h2>BUGS</h2>
<p style="margin-left:11%; margin-top: 1em">The
<b>−I</b> option does not yet work properly with time
series data (e.g., <b>−f</b>0T). Thus, such variable
intervals as months and years are not calculated. Instead,
specify your interval in the same units as the current
setting of <b><A HREF="gmtdefaults.html#TIME_UNIT">TIME_UNIT</A></b>.</p>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<p style="margin-left:11%; margin-top: 1em"><i><A HREF="GMT.html">GMT</A></i>(1)</p>
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