[gnuastro-commits] master 52d3868: MakeProfiles: rounding of sub-pixel center at 1/1000000 from 1/100

[Mohammad Akhlaghi]

branch: master
commit 52d38688c0aee15befa1236a7e26a82010bab5af
Author: Mohammad Akhlaghi <address@hidden>
Commit: Mohammad Akhlaghi <address@hidden>

    MakeProfiles: rounding of sub-pixel center at 1/1000000 from 1/100
    
    Until now, to fix floating point issues (especially when converting from
    WCS), we were rounding subpixel, image coordinates to 1/100. As a result,
    for example a central pixel value of 2.499 would be rounded to
    2.5. However, especially when using large oversampling, such levels of
    precision are necessary. We are also dealing with double-precision floating
    point types which are accurate to roughly 15 decimals. SO the rounding to
    1/100 was not too accurate and could cause unexpected behavior.
    
    To fix this problem, in MakeProfile's `oneprofile_center_oversampled'
    function, the rounding is now set as a variable `r', and given a value of
    1000000. This is also arbitrary and hard-coded in the source, but
    currently, I don't see any need to change it. If we later feel the user
    must be able to change it, we can define it as an option.
    
    While inspecting the code, a few typos and edits were also fixed the
    comments to make them more clear to read. Also, the name of the
    `oneprof_set_prof_params' function was corrected to
    `oneprofile_set_prof_params' (which is the correct format!).
    
    This bug was reported by Roberto Baena Gallé.
    
    This fixes bug #56641.
---
 NEWS                         |  1 +
 bin/mkprof/mkprof.c          | 18 +++++++++---------
 bin/mkprof/oneprofile.c      |  7 +++----
 bin/mkprof/oneprofile.h      |  2 +-
 doc/announce-acknowledge.txt |  1 +
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/NEWS b/NEWS
index 2d2a501..976b7bd 100644
--- a/NEWS
+++ b/NEWS
@@ -135,6 +135,7 @@ See the end of the file for license conditions.
   bug #56324: Column metadata not usable when input is from pipe/stdin.
   bug #56424: Warp crashes with empty string given to options.
   bug #56480: Segfault in statistics library's histogram function.
+  bug #56641: MakeProfile's center position changes based on precision.
 
 
 
diff --git a/bin/mkprof/mkprof.c b/bin/mkprof/mkprof.c
index 17c623b..7612f77 100644
--- a/bin/mkprof/mkprof.c
+++ b/bin/mkprof/mkprof.c
@@ -320,7 +320,7 @@ mkprof_build_single(struct mkonthread *mkp, long *fpixel_i, 
long *lpixel_i,
      overlapping region. */
   if(p->out)
     {
-      /* Note that `fpixel_o' and `lpixel_o' were in the un-oversampled
+      /* Note that `fpixel_i' and `lpixel_o' were in the un-oversampled
          image, they are also in the FITS coordinates. */
       for(i=0;i<ndim;++i)
         {
@@ -465,20 +465,20 @@ mkprof_build(void *inparam)
   /* Make each profile that was specified for this thread. */
   for(i=0; mkp->indexs[i]!=GAL_BLANK_SIZE_T; ++i)
     {
-      /* Create a new builtqueue element with all the information. fbq
-         will be used when we want to add ibq to p->bq. It is defined
-         so we don't have to waste time traversing the ibq. Its
-         characteristic compared to the other elements of ibq is that
-         fbq->next==NULL. So to add ibq to p->bq, we just have to set
-         fbq->next=p->bq and then set p->bq to ibq.*/
+      /* Create a new builtqueue element with all the information. `fbq'
+         will be used when we want to add `ibq' to `p->bq'. It is defined
+         so we don't have to waste time traversing the `ibq'. Its
+         characteristic compared to the other elements of `ibq' is that
+         `fbq->next==NULL'. So to add ibq to p->bq, we just have to set
+         `fbq->next=p->bq' and then set `p->bq' to `ibq'.*/
       builtqueue_addempty(&mkp->ibq);
       ibq=mkp->ibq;
       id=ibq->id=mkp->indexs[i];
       if(fbq==NULL) fbq=ibq;
 
 
-      /* Write the necessary parameters for this profile into mkp.*/
-      oneprof_set_prof_params(mkp);
+      /* Write the necessary parameters for this profile into `mkp'.*/
+      oneprofile_set_prof_params(mkp);
 
 
       /* Find the bounding box size (NOT oversampled). */
diff --git a/bin/mkprof/oneprofile.c b/bin/mkprof/oneprofile.c
index 471fdd4..d01ffa2 100644
--- a/bin/mkprof/oneprofile.c
+++ b/bin/mkprof/oneprofile.c
@@ -62,19 +62,18 @@ oneprofile_center_oversampled(struct mkonthread *mkp)
 {
   struct mkprofparams *p=mkp->p;
 
-  double *dim;
   long os=p->oversample;
+  double *dim, r=1000000;
   size_t i, id=mkp->ibq->id;
   double val, pixfrac, intpart;
 
   for(i=0;i<p->ndim;++i)
     {
       dim = i==0 ? p->x : p->y;
-
       pixfrac = modf(fabs(dim[id]), &intpart);
       val     = ( os*(mkp->width[i]/2 + pixfrac)
                   + (pixfrac<0.5f ? os/2 : -1*os/2-1) );
-      mkp->center[i] = round(val*100)/100;
+      mkp->center[i] = round(val*r)/r;
     }
 }
 
@@ -515,7 +514,7 @@ oneprofile_ispsf(uint8_t fcode)
 
 /* Prepare all the parameters for any type of profile. */
 void
-oneprof_set_prof_params(struct mkonthread *mkp)
+oneprofile_set_prof_params(struct mkonthread *mkp)
 {
   struct mkprofparams *p=mkp->p;
 
diff --git a/bin/mkprof/oneprofile.h b/bin/mkprof/oneprofile.h
index acc7aea..e38b61e 100644
--- a/bin/mkprof/oneprofile.h
+++ b/bin/mkprof/oneprofile.h
@@ -29,7 +29,7 @@ int
 oneprofile_ispsf(uint8_t fcolvalue);
 
 void
-oneprof_set_prof_params(struct mkonthread *mkp);
+oneprofile_set_prof_params(struct mkonthread *mkp);
 
 void
 oneprofile_make(struct mkonthread *mkp);
diff --git a/doc/announce-acknowledge.txt b/doc/announce-acknowledge.txt
index 23858a9..241dcec 100644
--- a/doc/announce-acknowledge.txt
+++ b/doc/announce-acknowledge.txt
@@ -1,6 +1,7 @@
 Alphabetically ordered list to acknowledge in the next release.
 
 Hamed Altafi
+Roberto Baena Gallé
 Zahra Bagheri
 Leindert Boogaard
 Bruno Haible