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>nside2npix</TITLE> 7<META NAME="description" CONTENT="nside2npix"> 8<META NAME="keywords" CONTENT="subroutines"> 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="subroutines.css"> 27 28<LINK REL="next" HREF="sub_nside2npweights.htm"> 29<LINK REL="previous" HREF="sub_npix2nside.htm"> 30<LINK REL="next" HREF="sub_nside2npweights.htm"> 31</HEAD> 32 33<body text="#000000" bgcolor="#FFFFFA"> 34 35<DIV CLASS="navigation"><!--Navigation Panel--> 36<A 37 HREF="sub_npix2nside.htm"> 38<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 39<A 40 HREF="sub_HEALPix_F90_subroutines.htm"> 41<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 42<A 43 HREF="sub_nside2npweights.htm"> 44<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 45<A ID="tex2html428" 46 HREF="sub_TABLE_CONTENTS.htm"> 47<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 48<BR> 49<B> Previous:</B> <A 50 HREF="sub_npix2nside.htm">npix2nside</A> 51 52<B>Up:</B> <A 53 HREF="sub_HEALPix_F90_subroutines.htm">HEALPix/F90 subroutines</A> 54 55<B> Next:</B> <A 56 HREF="sub_nside2npweights.htm">nside2npweights</A> 57<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 58<!--End of Navigation Panel--> 59 60<H1><A ID="SECTION6800"></A> 61<A ID="sub:nside2npix"></A> 62<BR> 63 64</H1> 65 66<P> 67<b><font size=+6><FONT COLOR="#CC0000">nside2npix</FONT></font></b><hr> 68<H3>Function to provide the number of pixels <!-- MATH 69 $N_{\mathrm{pix}}$ 70 --> 71<SPAN CLASS="MATH"><I>N</I><SUB>pix</SUB></SPAN> over the full sky corresponding 72to resolution parameter <!-- MATH 73 $N_{\mathrm{side}}$ 74 --> 75<SPAN CLASS="MATH"><I>N</I><SUB>side</SUB></SPAN>. 76</H3> 77Location in HEALPix directory tree: <a href="https://sourceforge.net/p/healpix/code/1005/tree/trunk/src/f90/mod/pix_tools.F90"><b>src/f90/mod/pix_tools.F90</b></a> 78 79<P> 80<hr><h1>FORMAT </h1><h3>var=<FONT COLOR="#CC0000">nside2npix</FONT>( 81<A HREF="#sub:nside2npix:nside">nside</A> 82)</h3> 83 84<P> 85<hr><H1>ARGUMENTS</H1> 86 87<TABLE CELLPADDING=3 BORDER="1"> 88<TR><TH ALIGN="LEFT" VALIGN="TOP" WIDTH=150><SPAN CLASS="textbf">name & dimensionality</SPAN></TH> 89<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=25><SPAN CLASS="textbf">kind</SPAN></TH> 90<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=50><SPAN CLASS="textbf">in/out</SPAN></TH> 91<TH ALIGN="LEFT" VALIGN="TOP" WIDTH=225><SPAN CLASS="textbf">description</SPAN></TH> 92</TR> 93<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150> </TD> 94<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25> </TD> 95<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50> </TD> 96<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225> </TD> 97</TR> 98<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150> 99nside<A ID="sub:nside2npix:nside"></A></TD> 100<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25>I4B</TD> 101<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50>IN</TD> 102<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225>the <!-- MATH 103 $N_{\mathrm{side}}$ 104 --> 105<SPAN CLASS="MATH"><I>N</I><SUB>side</SUB></SPAN> parameter of the map.</TD> 106</TR> 107<TR><TD ALIGN="LEFT" VALIGN="TOP" WIDTH=150>var</TD> 108<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=25>I8B</TD> 109<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50>OUT</TD> 110<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=225>the number of pixels <!-- MATH 111 $N_{\mathrm{pix}}$ 112 --> 113<SPAN CLASS="MATH"><I>N</I><SUB>pix</SUB></SPAN> of the map. If <!-- MATH 114 $N_{\mathrm{side}}$ 115 --> 116<SPAN CLASS="MATH"><I>N</I><SUB>side</SUB></SPAN> is valid (a power of 2 in 117<!-- MATH 118 $\{1,\ldots,2^{28}=268435456\}$ 119 --> 120<SPAN CLASS="MATH"><IMG STYLE="height: 2.45ex; vertical-align: -0.68ex; " SRC="sub_img151.png" 121 ALT="$\{1,\ldots,2^{28}=268435456\}$"></SPAN>), <!-- MATH 122 $N_{\mathrm{pix}}=12N_{\mathrm{side}}^2$ 123 --> 124<SPAN CLASS="MATH"><I>N</I><SUB>pix</SUB>=12<I>N</I><SUB>side</SUB><SUP><i>2</i></SUP></SPAN> is returned; if not, an error message is 125issued and -1 is returned.</TD> 126</TR> 127</TABLE> 128 129<P> 130<HR><H1>EXAMPLE:</H1> 131<tt>use <A HREF="sub_healpix_modules_module.htm#sub:healpix_modules">healpix_modules</A> 132<BR> 133integer(<A HREF="sub_healpix_types_module.htm#sub:healpix_types">I8B</A>) :: npix 134<BR> 135npix= nside2npix(256) 136<BR></tt> 137<blockquote> 138Returns the number of <b>HEALPix</b> pixels (786432) for the resolution 139parameter 256. 140</blockquote> 141<hr><H1>RELATED ROUTINES</H1><h3>This section lists the routines related to <b><FONT COLOR="#CC0000">nside2npix</FONT></b></h3> 142 143 <DL COMPACT><DT> 144<B><A HREF="sub_npix2nside.htm#sub:npix2nside">npix2nside</A></B> 145<DD>returns resolution parameter corresponding to the number of pixels. 146</DL> 147 148<P> 149 150 151<P> 152 153<P> 154 155<DIV CLASS="navigation"><HR> 156<!--Navigation Panel--> 157<A 158 HREF="sub_npix2nside.htm"> 159<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 160<A 161 HREF="sub_HEALPix_F90_subroutines.htm"> 162<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 163<A 164 HREF="sub_nside2npweights.htm"> 165<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 166<A ID="tex2html428" 167 HREF="sub_TABLE_CONTENTS.htm"> 168<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 169<BR> 170<B> Previous:</B> <A 171 HREF="sub_npix2nside.htm">npix2nside</A> 172 173<B>Up:</B> <A 174 HREF="sub_HEALPix_F90_subroutines.htm">HEALPix/F90 subroutines</A> 175 176<B> Next:</B> <A 177 HREF="sub_nside2npweights.htm">nside2npweights</A> 178<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 179<!--End of Navigation Panel--> 180<ADDRESS> 181Version 3.50, 2018-12-10 182</ADDRESS> 183</BODY> 184</HTML> 185
