added pj_transform

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@891 4e78687f-474d-0410-85f9-8d5e500ac6b2

1 files changed, 13 insertions, 0 deletions

diff --git a/man/man3/pj_init.3 b/man/man3/pj_init.3
index 306339e1..a50b2860 100644
--- a/man/man3/pj_init.3
+++ b/man/man3/pj_init.3
@@ -21,6 +21,9 @@ projUV pj_fwd(projUV val, PJ *proj)
 
 projUV pj_inv(projUV val, PJ *proj)
 
+int pj_transform(PJ *src_cs, PJ *dst_cs, long point_count, 
+                 double *x, double *y, double *z)
+               
 void pj_free(PJ *proj)
 
 .SH DESCRIPTION
@@ -48,6 +51,16 @@ an inverse projection.
 If the projection does not have an inverse the PJ structure element
 \fIinv\fR will be NULL.
 
+The \fBpj_transform\fR 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 \fBpj_fwd\fR and \fBpj_inv\fR it is also allowable
+for the coordinate system definitions (\fBPJ *\fR) to be geographic coordinate
+systems (defined as +proj=latlong).  The \fBx\fR, \fBy\fR and \fBz\fR arrays
+contain the input values of the points, and are replaced with the output
+values.  The function returns the number of points successfully transformed.
+
 Memory associated with the projection may be freed with \fBpj_free\fR.
 .SH EXAMPLE
 The following program reads latitude and longitude values in decimal