[gnuastro-commits] master 75d7dd6c 2/2: Statistics: MAD only calculated in one-row outputs with --mad

[Mohammad Akhlaghi]

branch: master
commit 75d7dd6c8582b523598a2f0c65d961d255922df9
Author: Mohammad Akhlaghi <mohammad@akhlaghi.org>
Commit: Mohammad Akhlaghi <mohammad@akhlaghi.org>

    Statistics: MAD only calculated in one-row outputs with --mad
    
    Until now, if the user requested '--median' or '--mad', the statistics
    program would call 'gal_statistics_median_mad' (which calculates both!). As
    a result, if the user just wanted the median (and not the MAD), the program
    would un-necessarily become slow (to calculate the un-used MAD!).
    
    With this commit, if the MAD is not requested, the Statistics program will
    just call 'gal_statistics_median' to only do the requested job and nothing
    extra.
---
 bin/statistics/statistics.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/bin/statistics/statistics.c b/bin/statistics/statistics.c
index f01db3c0..5f0b512f 100644
--- a/bin/statistics/statistics.c
+++ b/bin/statistics/statistics.c
@@ -122,10 +122,10 @@ statistics_print_one_row(struct statisticsparams *p)
   int mustfree;
   char *toprint;
   double arg, *d;
-  uint8_t clipflag;
-  gal_list_i32_t *tmp;
   gal_data_t *medmad=NULL;
   size_t dsize=1, counter;
+  uint8_t clipflag, hasmad;
+  gal_list_i32_t *tmp, *ttmp;
   gal_data_t *sclip=NULL, *mclip=NULL;
   gal_data_t *sum=NULL, *meanstd=NULL, *modearr=NULL;
   gal_data_t *tmpv, *out=NULL, *num=NULL, *min=NULL, *max=NULL;
@@ -155,7 +155,18 @@ statistics_print_one_row(struct statisticsparams *p)
         break;
       case UI_KEY_MAD:
       case UI_KEY_MEDIAN:
-        medmad = medmad ? medmad : gal_statistics_median_mad(p->input, 0);
+        if(medmad==NULL)
+          {
+            /* If MAD is requested, the median is a free byproduct. But if
+               MAD is not requested, we don't want to waste the user's time
+               for calculating it. */
+            hasmad=0;
+            for(ttmp=p->singlevalue; ttmp!=NULL; ttmp=ttmp->next)
+              if(ttmp->v==UI_KEY_MAD) hasmad=1;
+            medmad = ( hasmad
+                       ? gal_statistics_median_mad(p->input, 0)
+                       : gal_statistics_median(p->input, 0) );
+          }
         break;
       case UI_KEY_MODE:
       case UI_KEY_MODEQUANT: