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>write_fits_cut4 </TITLE> 7<META NAME="description" CONTENT="write_fits_cut4 "> 8<META NAME="keywords" CONTENT="idl"> 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="idl.css"> 27 28<LINK REL="next" HREF="idl_write_fits_map.htm"> 29<LINK REL="previous" HREF="idl_vec2ang.htm"> 30<LINK REL="next" HREF="idl_write_fits_map.htm"> 31</HEAD> 32 33<body text="#000000" bgcolor="#FFFFFA"> 34 35<DIV CLASS="navigation"><!--Navigation Panel--> 36<A 37 HREF="idl_vec2ang.htm"> 38<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 39<A 40 HREF="idl_HEALPix_IDL_subroutines.htm"> 41<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 42<A 43 HREF="idl_write_fits_map.htm"> 44<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 45<A ID="tex2html421" 46 HREF="idl_TABLE_CONTENTS.htm"> 47<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 48<BR> 49<B> Previous:</B> <A 50 HREF="idl_vec2ang.htm">vec2ang</A> 51 52<B>Up:</B> <A 53 HREF="idl_HEALPix_IDL_subroutines.htm">HEALPix/IDL subroutines</A> 54 55<B> Next:</B> <A 56 HREF="idl_write_fits_map.htm">write_fits_map</A> 57<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 58<!--End of Navigation Panel--> 59 60<H1><A ID="SECTION7400"></A> 61<A ID="idl:write_fits_cut4"></A> 62<BR> 63 64</H1> 65 66<P> 67<b><font size=+6><FONT COLOR="#CC0000">write_fits_cut4 </FONT></font></b><hr> 68<H3>This IDL facility writes out a cut sky <b>HEALPix</b> map into a FITS file according to 69the <b>HEALPix</b> convention. The format used for the 70FITS file follows the one used for Boomerang98 and is adapted from 71COBE/DMR. This routine can be used to store polarized maps, where the 72information relative to the Stokes parameters I, Q and U are placed in extension 730, 1 and 2 respectively by successive invocation of the routine.</H3> 74Location in HEALPix directory tree: <a href="https://sourceforge.net/p/healpix/code/1005/tree/trunk/src/idl/fits/write_fits_cut4.pro"><b>src/idl/fits/write_fits_cut4.pro</b></a> 75 76<P> 77<hr><h1>FORMAT </h1><h3>IDL> 78WRITE_FITS_CUT4 , <A HREF="#idl:write_fits_cut4:File">File</A>, <A HREF="#idl:write_fits_cut4:Pixel">Pixel</A>, <A HREF="#idl:write_fits_cut4:Signal">Signal</A>[, <A HREF="#idl:write_fits_cut4:N_Obs">N_Obs</A>, <A HREF="#idl:write_fits_cut4:Serror">Serror</A>, 79<A HREF="#idl:write_fits_cut4:COORDSYS">COORDSYS=</A>, 80<A HREF="#idl:write_fits_cut4:EXTENSION">EXTENSION=</A>, 81<A HREF="#idl:write_fits_cut4:HDR">HDR=</A>, 82<A HREF="#idl:write_fits_cut4:NESTED">/NESTED</A>, 83<A HREF="#idl:write_fits_cut4:NSIDE">NSIDE=</A>, 84<A HREF="#idl:write_fits_cut4:ORDERING">ORDERING=</A>, 85<A HREF="#idl:write_fits_cut4:POLARISATION">/POLARISATION</A>, 86<A HREF="#idl:write_fits_cut4:RING">/RING</A>, 87<A HREF="#idl:write_fits_cut4:UNITS">UNITS=</A>, 88<A HREF="#idl:write_fits_cut4:XHDR">XHDR=</A>, 89<A HREF="#idl:write_fits_cut4:HELP">HELP=</A>] 90 91</h3> 92 93<P> 94<hr> 95<H1>QUALIFIERS</H1> 96 97 <DL COMPACT><DT> 98<B>File</B> 99<DD><A ID="idl:write_fits_cut4:File"></A> name of a FITS file in which the map is to be written 100 101<P> 102<DT> 103<B>Pixel</B> 104<DD><A ID="idl:write_fits_cut4:Pixel"></A> (LONG or LONG64 vector), 105<BR> 106index of observed (or valid) pixels 107 108<P> 109<DT> 110<B>Signal</B> 111<DD><A ID="idl:write_fits_cut4:Signal"></A> (FLOAT or DOUBLE vector, same size as Pixel), 112<BR> 113value of signal in each observed pixel 114 115<P> 116<DT> 117<B>N_Obs</B> 118<DD><A ID="idl:write_fits_cut4:N_Obs"></A> (LONG or INT or LONG64 vector, Optional, same size as Pixel), 119<BR> 120number of 121 observation per pixel. 122<BR> 123If absent, the field <TT>N_OBS</TT> will take a value of 1 in the output file. 124 If set to a scalar constant, <TT>N_OBS</TT> will take this value in the 125 output file 126 127<P> 128<DT> 129<B>Serror</B> 130<DD><A ID="idl:write_fits_cut4:Serror"></A> (FLOAT or DOUBLE vector, Optional, same size as Pixel) 131<BR><EM>rms</EM> of signal in pixel, for white noise, 132 this is <!-- MATH 133 $\propto 1/\sqrt{{\rm n\_obs}}$ 134 --> 135<SPAN CLASS="MATH"><IMG STYLE="height: 2.51ex; vertical-align: -0.68ex; " SRC="idl_img102.png" 136 ALT="$\propto 1/\sqrt{{\rm n\_obs}}$"></SPAN> 137<BR> 138If absent, the field <TT>SERROR</TT> will take a value of 0.0 in the output file. 139 If set to a scalar constant, <TT>SERROR</TT> will take this value in the 140 output file 141 142<P> 143</DL> 144 145<P> 146<hr><H1>KEYWORDS</H1> 147 148 <DL COMPACT><DT> 149<B>COORDSYS=</B> 150<DD><A ID="idl:write_fits_cut4:COORDSYS"></A> (optional), 151<BR> 152if set to either 'C', 'E' or 'G', specifies that the 153 Healpix coordinate system is respectively Celestial=equatorial, 154 Ecliptic or Galactic. 155 (The relevant keyword is then added/updated in the extension 156 header, but the map is NOT rotated) 157 158<P> 159<DT> 160<B>EXTENSION=</B> 161<DD><A ID="idl:write_fits_cut4:EXTENSION"></A> (optional), 162<BR> (0 based) extension number in which to write data. <b>default:</b>0. 163 If set to 0 (or not set) <EM>a new file is written from scratch</EM>. 164 If set to a value 165 larger than 1, the corresponding extension is added or 166 updated, as long as all previous extensions already exist. 167 All extensions of the same file should use the same ORDERING, 168 NSIDE and COORDSYS. 169 170<P> 171<DT> 172<B>HDR=</B> 173<DD><A ID="idl:write_fits_cut4:HDR"></A>(optional), 174<BR> 175String array containing the information to be put in 176 the primary header. 177 178<P> 179<DT> 180<B>/NESTED</B> 181<DD><A ID="idl:write_fits_cut4:NESTED"></A>(optional) 182 if set, specifies that the map is in the NESTED ordering 183 scheme 184<BR> <i>see also:</i>Ordering and Ring 185 186<P> 187<DT> 188<B>NSIDE=</B> 189<DD><A ID="idl:write_fits_cut4:NSIDE"></A> (optional), 190<BR> 191scalar integer, <b>HEALPix</b> resolution parameter of the 192 data set. The resolution parameter should be made 193 available to the FITS file, either thru this 194 qualifier, or via the header (see XHDR). 195 196<P> 197<DT> 198<B>ORDERING=</B> 199<DD><A ID="idl:write_fits_cut4:ORDERING"></A> (optional), 200<BR> 201if set to either 'ring' or 'nested' (case un-sensitive), 202 specifies that the map is respectively in RING or NESTED 203 ordering scheme 204<BR> <i>see also:</i>Nested and Ring 205<BR> 206The ordering information should be made 207 available to the FITS file, either thru a combination 208 of Ordering/Ring/Nested, or via the header (see XHDR). 209 210<P> 211<DT> 212<B>/POLARISATION</B> 213<DD><A ID="idl:write_fits_cut4:POLARISATION"></A> specifies that file will contain the I, Q and U polarisation 214 Stokes parameter in extensions 0, 1 and 2 respectively, and sets the 215FITS header keywords accordingly 216 217<P> 218<DT> 219<B>/RING</B> 220<DD><A ID="idl:write_fits_cut4:RING"></A> if set, specifies that the map is in the RING ordering 221 scheme 222<BR> <i>see also:</i>Ordering and Nested 223 224<P> 225<DT> 226<B>UNITS=</B> 227<DD><A ID="idl:write_fits_cut4:UNITS"></A> (optional), 228<BR> 229string describing the physical units of the data set (only applies 230 to Signal and Serror) 231 232<P> 233<DT> 234<B>XHDR=</B> 235<DD><A ID="idl:write_fits_cut4:XHDR"></A>(optional), 236<BR> 237String array containing the information to be put in 238 the extension header. 239 240<P> 241<DT> 242<B>HELP=</B> 243<DD><A ID="idl:write_fits_cut4:HELP"></A>(optional), 244<BR> 245if set, an extensive help is displayed, and no file is written 246 247<P> 248</DL> 249 250<P> 251<hr> 252<H1>DESCRIPTION</H1> 253<blockquote> 254<br><br></blockquote> 255 256<P> 257<hr><H1>RELATED ROUTINES</H1><h3>This section lists the routines related to <b><FONT COLOR="#CC0000">write_fits_cut4 </FONT></b></h3> 258 259 <DL COMPACT><DT> 260<B>idl</B> 261<DD>version 6.4 or more is necessary to run <FONT COLOR="#CC0000">write_fits_cut4 </FONT> 262 <DT> 263<B><A HREF="idl_read_fits_cut4.htm#idl:read_fits_cut4">read_fits_cut4</A></B> 264<DD>This <b>HEALPix</b> IDL facility can be used to read in maps 265 written by <FONT COLOR="#CC0000">write_fits_cut4 </FONT>. 266 <DT> 267<B><A HREF="#idl:write_fits_cut4">write_fits_cut4</A>, 268<A HREF="idl_write_fits_map.htm#idl:write_fits_map">write_fits_map</A></B> 269<DD><DT> 270<B><A HREF="idl_write_tqu.htm#idl:write_tqu">write_tqu</A>, 271<A HREF="idl_write_fits_sb.htm#idl:write_fits_sb">write_fits_sb</A></B> 272<DD><b>HEALPix</b> IDL routines to write cut-sky maps, full-sky maps, polarized full-sky maps and 273arbitrary data sets into FITS files 274 <DT> 275<B>sxaddpar</B> 276<DD>This IDL routine (included in <b>HEALPix</b> package) can be used to update 277 or add FITS keywords to the header in <TT>HDR</TT> and <TT>XHDR</TT> 278 </DL> 279 280<P> 281<hr><H1>EXAMPLE # 1:</H1> 282<tt><TABLE CELLPADDING=3> 283<TR><TD ALIGN="LEFT"><FONT COLOR="#CC0000">write_fits_cut4 </FONT>, 'map_cut.fits', pixel, temperature, /ring,nside=32, /pol</TD> 284<TD ALIGN="LEFT"> </TD> 285</TR> 286</TABLE></tt> 287<blockquote>writes in 'map_cut.fits' a FITS file containing the temperature measured in a 288 set of <b>HEALPix</b> pixel. 289</blockquote> 290<hr><H1>EXAMPLE # 2:</H1> 291<tt><TABLE CELLPADDING=3> 292<TR><TD ALIGN="LEFT"><FONT COLOR="#CC0000">write_fits_cut4 </FONT>, 'tqu_cut.fits', pixel, temperature, n_t, s_t, $</TD> 293</TR> 294<TR><TD ALIGN="LEFT">/ring, nside=32, /pol</TD> 295</TR> 296<TR><TD ALIGN="LEFT"><FONT COLOR="#CC0000">write_fits_cut4 </FONT>, 'tqu_cut.fits', pixel, qstokes, n_q, s_q, $</TD> 297</TR> 298<TR><TD ALIGN="LEFT">/ring, nside=32, /pol, ext=1</TD> 299</TR> 300<TR><TD ALIGN="LEFT"><FONT COLOR="#CC0000">write_fits_cut4 </FONT>, 'tqu_cut.fits', pixel, ustokes, n_u, s_u, $</TD> 301</TR> 302<TR><TD ALIGN="LEFT">/ring, nside=32, /pol, ext=2</TD> 303</TR> 304</TABLE></tt> 305<blockquote>writes in 'tqu_cut.fits' a FITS file with three extensions, each of them containing 306information on the observed pixel, the measured signal, the number of 307observations and noise per pixel, for the three Stokes parameters I, Q and U 308respectively. The <b>HEALPix</b> ring ordered scheme and the resolution <!-- MATH 309 $N_{\mathrm{side}}=32$ 310 --> 311<SPAN CLASS="MATH"><I>N</I><SUB>side</SUB>=32</SPAN> is assumed. 312</blockquote> 313 314<P> 315 316<P> 317 318<DIV CLASS="navigation"><HR> 319<!--Navigation Panel--> 320<A 321 HREF="idl_vec2ang.htm"> 322<IMG WIDTH="63" HEIGHT="24" ALT="previous" SRC="prev.png"></A> 323<A 324 HREF="idl_HEALPix_IDL_subroutines.htm"> 325<IMG WIDTH="26" HEIGHT="24" ALT="up" SRC="up.png"></A> 326<A 327 HREF="idl_write_fits_map.htm"> 328<IMG WIDTH="37" HEIGHT="24" ALT="next" SRC="next.png"></A> 329<A ID="tex2html421" 330 HREF="idl_TABLE_CONTENTS.htm"> 331<IMG WIDTH="65" HEIGHT="24" ALT="contents" SRC="contents.png"></A> 332<BR> 333<B> Previous:</B> <A 334 HREF="idl_vec2ang.htm">vec2ang</A> 335 336<B>Up:</B> <A 337 HREF="idl_HEALPix_IDL_subroutines.htm">HEALPix/IDL subroutines</A> 338 339<B> Next:</B> <A 340 HREF="idl_write_fits_map.htm">write_fits_map</A> 341<B> Top:</B> <a href="main.htm">Main Page</a></DIV> 342<!--End of Navigation Panel--> 343<ADDRESS> 344Version 3.50, 2018-12-10 345</ADDRESS> 346</BODY> 347</HTML> 348
