<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2002-2-1 (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>O.3.3 Prescribed label placements</TITLE> <META NAME="description" CONTENT="O.3.3 Prescribed label placements"> <META NAME="keywords" CONTENT="GMT_Docs"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="GMT_Docs.css"> <LINK REL="next" HREF="node246.html"> <LINK REL="previous" HREF="node244.html"> <LINK REL="up" HREF="node242.html"> <LINK REL="next" HREF="node246.html"> </HEAD> <BODY bgcolor="#ffffff"> <!--Navigation Panel--> <A NAME="tex2html6163" HREF="node246.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html6157" HREF="node242.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html6151" HREF="node244.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html6159" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <A NAME="tex2html6161" HREF="node256.html"> <IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A> <BR> <B> Next:</B> <A NAME="tex2html6164" HREF="node246.html">O.3.4 Label placement at</A> <B> Up:</B> <A NAME="tex2html6158" HREF="node242.html">O.3 Examples of Contour</A> <B> Previous:</B> <A NAME="tex2html6152" HREF="node244.html">O.3.2 Fixed number of</A> <B> <A NAME="tex2html6160" HREF="node1.html">Contents</A></B> <B> <A NAME="tex2html6162" HREF="node256.html">Index</A></B> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION003233000000000000000"> O.3.3 Prescribed label placements</A> </H2> <P> Here, we specify four points where we would like contour labels to be placed. Our points are not exactly on the contour lines so we give a nonzero ``slop'' to be used in the distance calculations: The point on the contour closest to our fixed points and within the given maximum distance will host the label. <P> <BR CLEAR="ALL"> <HR> <BR> <PRE>cat << EOF > fix.d 80 -8.5 55 -7.5 102 0 130 10.5 EOF pscoast -R50/160/-15/15 -JM5.3i -Glightgray -A500 -K -P > GMT_App_O_3.ps grdcontour geoid.nc -J -O -B20f10WSne -C10 -A20+d+s8 -Gffix.d/0.1i -S10 -T:LH >> GMT_App_O_3.ps </PRE> <BR CLEAR="ALL"> <HR> <P> The angle of the label is evaluated from the contour line geometry, and the final result is shown in Figure <A HREF="#fig:GMT_App_O_3">O.3</A>. <DIV ALIGN="CENTER"><A NAME="fig:GMT_App_O_3"></A><A NAME="33519"></A> <TABLE> <CAPTION ALIGN="BOTTOM"><STRONG>Figure:</STRONG> Four labels are positioned on the points along the contours that are closest to the locations given in the file <U>fix.d</U> in the <B>-Gf</B> option.</CAPTION> <TR><TD> <DIV ALIGN="CENTER"><IMG WIDTH="653" HEIGHT="195" ALIGN="BOTTOM" BORDER="0" SRC="img299.png" ALT="\includegraphics{scripts/GMT_App_O_3}"></DIV></TD></TR> </TABLE> </DIV> To aid in understanding the algorithm we chose to specify ``debug'' mode (<B>+d</B>) which placed a small circle at each of the fixed points. <P> <HR> <!--Navigation Panel--> <A NAME="tex2html6163" HREF="node246.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html6157" HREF="node242.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html6151" HREF="node244.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html6159" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <A NAME="tex2html6161" HREF="node256.html"> <IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A> <BR> <B> Next:</B> <A NAME="tex2html6164" HREF="node246.html">O.3.4 Label placement at</A> <B> Up:</B> <A NAME="tex2html6158" HREF="node242.html">O.3 Examples of Contour</A> <B> Previous:</B> <A NAME="tex2html6152" HREF="node244.html">O.3.2 Fixed number of</A> <B> <A NAME="tex2html6160" HREF="node1.html">Contents</A></B> <B> <A NAME="tex2html6162" HREF="node256.html">Index</A></B> <!--End of Navigation Panel--> <ADDRESS> Paul Wessel 2010-07-14 </ADDRESS> </BODY> </HTML>