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| author | Frank Warmerdam <warmerdam@pobox.com> | 2005-10-14 13:15:08 +0000 |
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| committer | Frank Warmerdam <warmerdam@pobox.com> | 2005-10-14 13:15:08 +0000 |
| commit | 87f150f1d9e634f83cb8945abce2577a46bd7ed7 (patch) | |
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diff --git a/html/man_pj_init.html b/html/man_pj_init.html new file mode 100644 index 00000000..e46a5a03 --- /dev/null +++ b/html/man_pj_init.html @@ -0,0 +1,159 @@ +Content-type: text/html + +<HTML><HEAD><TITLE>Manpage of PJ_INIT</TITLE> +</HEAD><BODY> +<H1>PJ_INIT</H1> +Section: Misc. Reference Manual Pages (3U)<BR>Updated: 2001/04/05 Rel. 4.4<BR><A HREF="#index">Index</A> +<A HREF="../index.html">Return to Main Contents</A><HR> + + + +<A NAME="lbAB"> </A> +<H2>NAME</H2> + +pj_init - initialize cartographic projection +<BR> + +pj_init_plus - initialize cartographic projection +<BR> + +pj_fwd - forward cartographic projection +<BR> + +pj_inv - inverse cartographic projection +<BR> + +pj_transform - transform between coordinate systems +<BR> + +pj_free - de-initialize projection +<A NAME="lbAC"> </A> +<H2>SYNOPSIS</H2> + +<PRE> +#include <<A HREF="file:/usr/include/proj_api.h">proj_api.h</A>> + +projPJ pj_init(int argc, char **argv) + +projPJ pj_init_plus(const char *defn) + +projUV pj_fwd(projUV val, projPJ proj) + +projUV pj_inv(projUV val, projPJ proj) + +int pj_transform(projPJ src_cs, projPJ dst_cs, long point_count, + double *x, double *y, double *z) + +void pj_free(projPJ proj) + +</PRE><A NAME="lbAD"> </A> +<H2>DESCRIPTION</H2> + +Procedure <B>pj_init</B> selects and initializes a cartographic projection +with its argument control parameters. +<B>Argc</B> is the number of elements in the array of control strings +<B>argv</B> that each contain individual cartographic control keyword +assignments (<TT>+</TT> <B>proj</B> arguments). +The list must contain at least the <B>proj=</B><I>projection</I> and +Earth's radius or elliptical parameters. +If the initialization of the projection is successful a valid +address is returned otherwise a NULL value. +<P> +The <B>pj_init_plus</B> function operates similarly to <B>pj_init</B> but +takes a single string containing the definition, with each parameter +prefixed with a plus sign. For example "+proj=utm +zone=11 +ellps=WGS84". +<P> +Once initialization is performed either forward or inverse +projections can be performed with the returned value of <B>pj_init</B> +used as the argument <B>proj</B>. +The argument structure <B>projUV</B> values <B>u</B> and <B>v</B> contain +respective longitude and latitude or x and y. +Latitude and longitude are in radians. +If a projection operation fails, both elements of <B>projUV</B> are +set to HUGE_VAL (defined in <I>math.h</I>). +<P> +<B>Note:</B> all projections have a forward mode, but some do not have +an inverse projection. +If the projection does not have an inverse the projPJ structure element +<I>inv</I> will be NULL. +<P> +The <B>pj_transform</B> function may be used to transform points between +the two provided coordinate systems. In addition to converting between +cartographic projection coordinates and geographic coordinates, this function +also takes care of datum shifts if possible between the source and destination +coordinate system. Unlike <B>pj_fwd</B> and <B>pj_inv</B> it is also allowable +for the coordinate system definitions (<B>PJ *</B>) to be geographic coordinate +systems (defined as +proj=latlong). The <B>x</B>, <B>y</B> and <B>z</B> arrays +contain the input values of the points, and are replaced with the output +values. The function returns zero on success, or the error number (also in +pj_errno) on failure. +<P> +Memory associated with the projection may be freed with <B>pj_free</B>. +<A NAME="lbAE"> </A> +<H2>EXAMPLE</H2> + +The following program reads latitude and longitude values in decimal +degress, performs Mercator projection with a Clarke 1866 ellipsoid and +a 33° latitude of true scale and prints the projected +cartesian values in meters: +<PRE> +<TT> +#include <<A HREF="file:/usr/include/proj_api.h">proj_api.h</A>> + +main(int argc, char **argv) { + char *args[] = { "proj=merc", "ellps=clrk66", "lat_ts=33" }; + projUV p; + projPJ pj; + + if (!(pj = pj_init(3, args))) + <A HREF="../man1/exit.1.html">exit</A>(1); + while (scanf("%lf %lf", &p.v, &p.u) == 2) { + p.u *= DEG_TO_RAD; + p.v *= DEG_TO_RAD; + p = pj_fwd(p, pj); + printf("%.2f\t%.2f\n", p.u, p.v); + } + exit(0); +} </TT> +<BR> +</PRE> + +<A NAME="lbAF"> </A> +<H2>LIBRARY</H2> + +libproj.a - library of projections and support procedures +<A NAME="lbAG"> </A> +<H2>SEE ALSO</H2> + +<B><A HREF="../man1U/proj.1U.html">proj</A>(1U),</B> + +<BR> + +<I>Cartographic Projection Procedures for the UNIX Environment---A User's Manual,</I> + +(Evenden, 1990, Open-file report 90-284). +<A NAME="lbAH"> </A> +<H2>HOME PAGE</H2> + +<A HREF="http://www.remotesensing.org/proj">http://www.remotesensing.org/proj</A> +<P> +<P> + +<HR> +<A NAME="index"> </A><H2>Index</H2> +<DL> +<DT><A HREF="#lbAB">NAME</A><DD> +<DT><A HREF="#lbAC">SYNOPSIS</A><DD> +<DT><A HREF="#lbAD">DESCRIPTION</A><DD> +<DT><A HREF="#lbAE">EXAMPLE</A><DD> +<DT><A HREF="#lbAF">LIBRARY</A><DD> +<DT><A HREF="#lbAG">SEE ALSO</A><DD> +<DT><A HREF="#lbAH">HOME PAGE</A><DD> +</DL> +<HR> +This document was created by +<A HREF="http://localhost/cgi-bin/man/man2html">man2html</A>, +using the manual pages.<BR> +Time: 13:14:22 GMT, October 14, 2005 +</BODY> +</HTML> |