From cf7de6ba70c8ea52ce67abfca82f38ebb3205f17 Mon Sep 17 00:00:00 2001
From: Dag Sverre Seljebotn <d.s.seljebotn@astro.uio.no>
Date: Mon, 30 Mar 2015 12:13:21 +0200
Subject: [PATCH] sharp_map_size and sharp_alm_count functions

---
 libsharp/sharp.c          | 24 ++++++++++++++++++++++++
 libsharp/sharp_lowlevel.h |  9 +++++++++
 2 files changed, 33 insertions(+)

diff --git a/libsharp/sharp.c b/libsharp/sharp.c
index f430364..e5a5634 100644
--- a/libsharp/sharp.c
+++ b/libsharp/sharp.c
@@ -169,6 +169,19 @@ ptrdiff_t sharp_alm_index (const sharp_alm_info *self, int l, int mi)
   return self->mvstart[mi]+self->stride*l;
   }
 
+ptrdiff_t sharp_alm_count(const sharp_alm_info *self)
+  {
+  ptrdiff_t result=0;
+  for (int im=0; im!=self->nm; ++im)
+    {
+    int m=self->mval[im];
+    ptrdiff_t x=(self->lmax + 1 - m);
+    if ((m!=0)&&((self->flags&SHARP_PACKED)!=0)) result+=2*x;
+    else result+=x;
+    }
+  return result;
+  }
+
 void sharp_destroy_alm_info (sharp_alm_info *info)
   {
   DEALLOC (info->mval);
@@ -226,6 +239,17 @@ void sharp_make_geom_info (int nrings, const int *nph, const ptrdiff_t *ofs,
   qsort(info->pair,info->npairs,sizeof(sharp_ringpair),ringpair_compare);
   }
 
+ptrdiff_t sharp_map_size(const sharp_geom_info *info)
+  {
+  ptrdiff_t result = 0;
+  for (int m=0; m<info->npairs; ++m)
+    {
+      result+=info->pair[m].r1.nph;
+      result+=(info->pair[m].r2.nph>=0) ? (info->pair[m].r2.nph) : 0;
+    }
+  return result;
+  }
+
 void sharp_destroy_geom_info (sharp_geom_info *geom_info)
   {
   DEALLOC (geom_info->pair);
diff --git a/libsharp/sharp_lowlevel.h b/libsharp/sharp_lowlevel.h
index 129a1b8..0260c37 100644
--- a/libsharp/sharp_lowlevel.h
+++ b/libsharp/sharp_lowlevel.h
@@ -134,6 +134,10 @@ void sharp_make_general_alm_info (int lmax, int nm, int stride, const int *mval,
     \note for a \a sharp_alm_info generated by sharp_make_alm_info() this is
     the index for the coefficient with the quantum numbers \a l, \a mi. */
 ptrdiff_t sharp_alm_index (const sharp_alm_info *self, int l, int mi);
+/*! Returns the number of alm coefficients described by \a self. If the SHARP_PACKED
+    flag is set, this is number of "real" coeffecients (for m < 0 and m >= 0),
+    otherwise it is the number of complex coefficients (with m>=0). */
+ptrdiff_t sharp_alm_count(const sharp_alm_info *self);
 /*! Deallocates the a_lm info object. */
 void sharp_destroy_alm_info (sharp_alm_info *info);
 
@@ -159,6 +163,11 @@ void sharp_make_geom_info (int nrings, const int *nph, const ptrdiff_t *ofs,
   const int *stride, const double *phi0, const double *theta,
   const double *wgt, sharp_geom_info **geom_info);
 
+/*! Counts the number of grid points needed for (the local part of) a map described
+    by \a info.
+ */
+ptrdiff_t sharp_map_size(const sharp_geom_info *info);
+
 /*! Deallocates the geometry information in \a info. */
 void sharp_destroy_geom_info (sharp_geom_info *info);