1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> 2 3<!--Converted with LaTeX2HTML 2018.3 (Released July 19, 2018) --> 4<HTML lang="EN"> 5<HEAD> 6<TITLE>ang2vec</TITLE> 7<META NAME="description" CONTENT="ang2vec"> 8<META NAME="keywords" CONTENT="csub"> 9<META NAME="resource-type" CONTENT="document"> 10<META NAME="distribution" CONTENT="global"> 11 12<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8"> 13<META NAME="viewport" CONTENT="width=device-width, initial-scale=1.0"> 14<META NAME="Generator" CONTENT="LaTeX2HTML v2018.3"> 15 <link rel='apple-touch-icon' sizes='180x180' href='images/favicons/apple-touch-icon.png?v=2017'> 16 <link rel='icon' type='image/png' sizes='32x32' href='images/favicons/favicon-32x32.png?v=2017'> 17 <link rel='icon' type='image/png' sizes='16x16' href='images/favicons/favicon-16x16.png?v=2017'> 18 <link rel='manifest' href='images/favicons/manifest.json?v=2017'> 19 <link rel='mask-icon' href='images/favicons/safari-pinned-tab.svg?v=2017' color='#5bbad5'> 20 <link rel='shortcut icon' href='images/favicons/favicon.ico?v=2017'> 21 <meta name='apple-mobile-web-app-title' content='HEALPix'> 22 <meta name='application-name' content='HEALPix'> 23 <meta name='msapplication-config' content='images/favicons/browserconfig.xml?v=2017'> 24 <meta name='theme-color' content='#ffffff'> 25 26<LINK REL="STYLESHEET" HREF="csub.css"> 27 28<LINK REL="next" HREF="csub_get_fits_size.htm"> 29<LINK REL="previous" HREF="csub_Note_on_C_routines.htm"> 30<LINK REL="next" HREF="csub_get_fits_size.htm"> 31</HEAD> 32 33<body text="#000000" bgcolor="#FFFFFA"> 34 35<DIV CLASS="navigation"><!--Navigation Panel--> 36<A 37 HREF="csub_Note_on_C_routines.htm"> 38<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 39<A 40 HREF="csub_HEALPix_C_subroutines.htm"> 41<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 42<A 43 HREF="csub_get_fits_size.htm"> 44<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 45<A ID="tex2html40" 46 HREF="csub_Contents.htm"> 47<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 48<BR> 49<B> Previous:</B> <A 50 HREF="csub_Note_on_C_routines.htm">Note on the C routines</A> 51 52<B>Up:</B> <A 53 HREF="csub_HEALPix_C_subroutines.htm">HEALPix/C subroutines</A> 54 55<B> Next:</B> <A 56 HREF="csub_get_fits_size.htm">get_fits_size</A> 57<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 58<!--End of Navigation Panel--> 59 60<H1><A ID="SECTION600"></A> 61<A ID="csub:ang2vec"></A> 62<BR> 63 64</H1> 65 66<P> 67<b><font size=+6><FONT COLOR="#CC0000">ang2vec</FONT></font></b><hr> 68<H3>Routine to convert the position angles <SPAN CLASS="MATH"><IMG STYLE="height: 2.33ex; vertical-align: -0.68ex; " SRC="csub_img5.png" 69 ALT="$(\theta,\phi) $"></SPAN> of a point on the sphere 70into its 3D position vector <SPAN CLASS="MATH">(<I>x</I>,<I>y</I>,<I>z</I>)</SPAN> with 71<!-- MATH 72 $x = \sin\theta\cos\phi$ 73 --> 74<SPAN CLASS="MATH"><IMG STYLE="height: 2.10ex; vertical-align: -0.55ex; " SRC="csub_img6.png" 75 ALT="$x = \sin\theta\cos\phi $"></SPAN>, <!-- MATH 76 $y=\sin\theta\sin\phi$ 77 --> 78<SPAN CLASS="MATH"><IMG STYLE="height: 2.10ex; vertical-align: -0.55ex; " SRC="csub_img7.png" 79 ALT="$y=\sin\theta\sin\phi $"></SPAN>, <SPAN CLASS="MATH"><IMG STYLE="height: 1.69ex; vertical-align: -0.10ex; " SRC="csub_img8.png" 80 ALT="$z=\cos\theta $"></SPAN>. 81</H3> 82Location in HEALPix directory tree: <a href="https://sourceforge.net/p/healpix/code/1005/tree/trunk/src/C/subs/chealpix.c"><b>src/C/subs/chealpix.c</b></a> 83 84<P> 85<hr><h1>FORMAT </h1><h3> 86void vec2ang(double theta, double phi, double *vector); 87</h3> 88 89<P> 90<hr><H1>ARGUMENTS</H1> 91 92<TABLE CELLPADDING=3 BORDER="1"> 93<TR><TH ALIGN="LEFT" VALIGN="TOP" WIDTH=150><SPAN CLASS="textbf">name & dimensionality</SPAN></TH> 94<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=50><SPAN CLASS="textbf">kind</SPAN></TH> 95<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=25><SPAN CLASS="textbf">in/out</SPAN></TH> 96<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=225><SPAN CLASS="textbf">description</SPAN></TH> 97</TR> 98<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150> </TD> 99<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50> </TD> 100<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25> </TD> 101<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225> </TD> 102</TR> 103<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150> 104theta</TD> 105<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50>double</TD> 106<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25>IN</TD> 107<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225>colatitude in radians measured southward from north pole (in 108 [0,<SPAN CLASS="MATH"><IMG STYLE="height: 1.11ex; vertical-align: -0.10ex; " SRC="csub_img2.png" 109 ALT="$\pi$"></SPAN>]).</TD> 110</TR> 111<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150>phi</TD> 112<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50>double</TD> 113<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25>IN</TD> 114<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225>longitude in radians measured eastward (in [0, <SPAN CLASS="MATH"><IMG STYLE="height: 1.57ex; vertical-align: -0.10ex; " SRC="csub_img9.png" 115 ALT="$2\pi$"></SPAN>]).</TD> 116</TR> 117<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150>vector(3)</TD> 118<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50>double</TD> 119<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25>OUT</TD> 120<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225>three dimensional cartesian position vector 121 <SPAN CLASS="MATH">(<I>x</I>,<I>y</I>,<I>z</I>)</SPAN>. The north pole is <SPAN CLASS="MATH">(0,0,1)</SPAN></TD> 122</TR> 123</TABLE> 124 125<P> 126<hr><H1>RELATED ROUTINES</H1><h3>This section lists the routines related to <b><FONT COLOR="#CC0000">ang2vec</FONT></b></h3> 127 128 <DL COMPACT><DT> 129<B><A HREF="csub_vec2ang.htm#csub:vec2ang">vec2ang</A></B> 130<DD>converts the 3D position vector of point into its position 131 angles on the sphere. 132 </DL> 133 134<P> 135 136 137<P> 138 139<P> 140 141<DIV CLASS="navigation"><HR> 142<!--Navigation Panel--> 143<A 144 HREF="csub_Note_on_C_routines.htm"> 145<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 146<A 147 HREF="csub_HEALPix_C_subroutines.htm"> 148<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 149<A 150 HREF="csub_get_fits_size.htm"> 151<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 152<A ID="tex2html40" 153 HREF="csub_Contents.htm"> 154<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 155<BR> 156<B> Previous:</B> <A 157 HREF="csub_Note_on_C_routines.htm">Note on the C routines</A> 158 159<B>Up:</B> <A 160 HREF="csub_HEALPix_C_subroutines.htm">HEALPix/C subroutines</A> 161 162<B> Next:</B> <A 163 HREF="csub_get_fits_size.htm">get_fits_size</A> 164<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 165<!--End of Navigation Panel--> 166<ADDRESS> 167Version 3.50, 2018-12-10 168</ADDRESS> 169</BODY> 170</HTML> 171
