<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<!--Converted with LaTeX2HTML 2008 (1.71)
original version by: Nikos Drakos, CBLU, University of Leeds
* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan
* with significant contributions from:
Jens Lippmann, Marek Rouchal, Martin Wilck and others -->
<HTML>
<HEAD>
<TITLE>Grid data</TITLE>
<META NAME="description" CONTENT="Grid data">
<META NAME="keywords" CONTENT="gnuplot">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<META NAME="Generator" CONTENT="LaTeX2HTML v2008">
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
<LINK REL="STYLESHEET" HREF="gnuplot.css">
<LINK REL="next" HREF="node342.html">
<LINK REL="previous" HREF="node336.html">
<LINK REL="up" HREF="node335.html">
<LINK REL="next" HREF="node342.html">
</HEAD>
<BODY >
<!--Navigation Panel-->
<A NAME="tex2html6087"
HREF="node342.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html6081"
HREF="node335.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html6075"
HREF="node340.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html6083"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<A NAME="tex2html6085"
HREF="node467.html">
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html6088"
HREF="node342.html">Splot overview</A>
<B> Up:</B> <A NAME="tex2html6082"
HREF="node335.html">Splot</A>
<B> Previous:</B> <A NAME="tex2html6076"
HREF="node340.html">Matrix</A>
<B> <A NAME="tex2html6084"
HREF="node1.html">Contents</A></B>
<B> <A NAME="tex2html6086"
HREF="node467.html">Index</A></B>
<BR>
<BR>
<!--End of Navigation Panel-->
<H2><A NAME="SECTION040262000000000000000"></A>
<A NAME="commands_splot_grid_data"></A><A NAME="splot_grid_data"></A><A NAME="grid_data"></A><A NAME="7813"></A>
<BR>
Grid data
</H2>
The 3D routines are designed for points in a grid format, with one sample,
datapoint, at each mesh intersection; the datapoints may originate from
either evaluating a function, see <B>set isosamples (p. <A HREF="node215.html#set_isosamples"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]" SRC="crossref.png"></A>)<A NAME="7815"></A></B>, or reading a datafile,
see <B>splot datafile (p. <A HREF="node336.html#splot_datafile"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]" SRC="crossref.png"></A>)<A NAME="7817"></A></B>. The term <TT>"</TT>isoline<TT>"</TT> is applied to the mesh lines for
both functions and data. Note that the mesh need not be rectangular in x
and y, as it may be parameterized in u and v, see <B>set isosamples (p. <A HREF="node215.html#set_isosamples"><IMG ALIGN="BOTTOM" BORDER="1" ALT="[*]" SRC="crossref.png"></A>)<A NAME="7821"></A></B>.
<P>
However, <B>gnuplot</B> does not require that format. In the case of functions,
'samples' need not be equal to 'isosamples', i.e., not every x-isoline
sample need intersect a y-isoline. In the case of data files, if there
are an equal number of scattered data points in each datablock, then
<TT>"</TT>isolines<TT>"</TT> will connect the points in a datablock, and <TT>"</TT>cross-isolines<TT>"</TT>
will connect the corresponding points in each datablock to generate a
<TT>"</TT>surface<TT>"</TT>. In either case, contour and hidden3d modes may give different
plots than if the points were in the intended format. Scattered data can be
converted to a {different} grid format with <B>set dgrid3d</B>.
<P>
The contour code tests for z intensity along a line between a point on a
y-isoline and the corresponding point in the next y-isoline. Thus a <B>splot</B>
contour of a surface with samples on the x-isolines that do not coincide with
a y-isoline intersection will ignore such samples. Try:
<BR>
<PRE>
set xrange [-pi/2:pi/2]; set yrange [-pi/2:pi/2]
set style function lp
set contour
set isosamples 10,10; set samples 10,10;
splot cos(x)*cos(y)
set samples 4,10; replot
set samples 10,4; replot
</PRE>
<BR>
<P>
<HR>
<!--Navigation Panel-->
<A NAME="tex2html6087"
HREF="node342.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html6081"
HREF="node335.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html6075"
HREF="node340.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html6083"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<A NAME="tex2html6085"
HREF="node467.html">
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html6088"
HREF="node342.html">Splot overview</A>
<B> Up:</B> <A NAME="tex2html6082"
HREF="node335.html">Splot</A>
<B> Previous:</B> <A NAME="tex2html6076"
HREF="node340.html">Matrix</A>
<B> <A NAME="tex2html6084"
HREF="node1.html">Contents</A></B>
<B> <A NAME="tex2html6086"
HREF="node467.html">Index</A></B>
<!--End of Navigation Panel-->
<ADDRESS>
2010-08-17
</ADDRESS>
</BODY>
</HTML>
