[gnuastro-commits] master ae760690: Library (arithmetic, units): GSL's M_PI instead of hardcoded 3.14

[Mohammad Akhlaghi]

branch: master
commit ae7606900c3a7dfedbd28cecc4e6449b68ccfcb1
Author: Pedram Ashofteh Ardakani <pedramardakani@pm.me>
Commit: Mohammad Akhlaghi <mohammad@akhlaghi.org>

    Library (arithmetic, units): GSL's M_PI instead of hardcoded 3.14
    
    Until now, the mathematical constant 'PI' was hardcoded and defined in
    programs that needed it.
    
    With this commit, we let GNU Scientific Library handle 'PI' which is
    defined as the 'M_PI' macro.
---
 lib/arithmetic.c | 23 ++++++++++++-----------
 lib/units.c      | 12 ++++++++----
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/lib/arithmetic.c b/lib/arithmetic.c
index 6f09ba83..31b2aa1c 100644
--- a/lib/arithmetic.c
+++ b/lib/arithmetic.c
@@ -2,9 +2,10 @@
 Arithmetic operations on data structures
 This is part of GNU Astronomy Utilities (Gnuastro) package.
 
-Original author:
+Corresponding author:
      Mohammad Akhlaghi <mohammad@akhlaghi.org>
 Contributing author(s):
+     Pedram Ashofteh Ardakani <pedramardakani@pm.me>
 Copyright (C) 2016-2022 Free Software Foundation, Inc.
 
 Gnuastro is free software: you can redistribute it and/or modify it
@@ -30,6 +31,7 @@ along with Gnuastro. If not, see 
<http://www.gnu.org/licenses/>.
 #include <stdarg.h>
 
 #include <gsl/gsl_rng.h>
+#include <gsl/gsl_math.h>
 #include <gsl/gsl_randist.h>
 
 #include <gnuastro/box.h>
@@ -513,7 +515,6 @@ arithmetic_function_unary(int operator, int flags, 
gal_data_t *in)
   uint8_t otype;
   int inplace=0;
   gal_data_t *o;
-  double pi=3.14159265358979323846264338327;
 
   /* The dataset may be empty. In this case, the output should also be empty
      (we can have tables and images with 0 rows or pixels!). */
@@ -557,7 +558,8 @@ arithmetic_function_unary(int operator, int flags, 
gal_data_t *in)
                          NULL, NULL, NULL);
     }
 
-  /* Start setting the operator and operands. */
+  /* Start setting the operator and operands. The mathematical constant
+     'PI' is imported from the GSL as M_PI. */
   switch(operator)
     {
     case GAL_ARITHMETIC_OP_SQRT:
@@ -567,17 +569,17 @@ arithmetic_function_unary(int operator, int flags, 
gal_data_t *in)
     case GAL_ARITHMETIC_OP_LOG10:
       UNIARY_FUNCTION_ON_ELEMENT( log10, +0, +0);         break;
     case GAL_ARITHMETIC_OP_SIN:
-      UNIARY_FUNCTION_ON_ELEMENT( sin,   *pi/180.0f, +0); break;
+      UNIARY_FUNCTION_ON_ELEMENT( sin,   *M_PI/180.0f, +0); break;
     case GAL_ARITHMETIC_OP_COS:
-      UNIARY_FUNCTION_ON_ELEMENT( cos,   *pi/180.0f, +0); break;
+      UNIARY_FUNCTION_ON_ELEMENT( cos,   *M_PI/180.0f, +0); break;
     case GAL_ARITHMETIC_OP_TAN:
-      UNIARY_FUNCTION_ON_ELEMENT( tan,   *pi/180.0f, +0); break;
+      UNIARY_FUNCTION_ON_ELEMENT( tan,   *M_PI/180.0f, +0); break;
     case GAL_ARITHMETIC_OP_ASIN:
-      UNIARY_FUNCTION_ON_ELEMENT( asin,  +0, *180.0f/pi); break;
+      UNIARY_FUNCTION_ON_ELEMENT( asin,  +0, *180.0f/M_PI); break;
     case GAL_ARITHMETIC_OP_ACOS:
-      UNIARY_FUNCTION_ON_ELEMENT( acos,  +0, *180.0f/pi); break;
+      UNIARY_FUNCTION_ON_ELEMENT( acos,  +0, *180.0f/M_PI); break;
     case GAL_ARITHMETIC_OP_ATAN:
-      UNIARY_FUNCTION_ON_ELEMENT( atan,  +0, *180.0f/pi); break;
+      UNIARY_FUNCTION_ON_ELEMENT( atan,  +0, *180.0f/M_PI); break;
     case GAL_ARITHMETIC_OP_SINH:
       UNIARY_FUNCTION_ON_ELEMENT( sinh,  +0, +0);         break;
     case GAL_ARITHMETIC_OP_COSH:
@@ -2003,7 +2005,6 @@ arithmetic_function_binary_flt(int operator, int flags, 
gal_data_t *il,
   int final_otype;
   size_t out_size, minmapsize;
   gal_data_t *l, *r, *o=NULL;
-  double pi=3.14159265358979323846264338327;
   int quietmmap=il->quietmmap && ir->quietmmap;
 
 
@@ -2072,7 +2073,7 @@ arithmetic_function_binary_flt(int operator, int flags, 
gal_data_t *il,
     case GAL_ARITHMETIC_OP_POW:
       BINFUNC_F_OPERATOR_SET( pow,   +0 );         break;
     case GAL_ARITHMETIC_OP_ATAN2:
-      BINFUNC_F_OPERATOR_SET( atan2, *180.0f/pi ); break;
+      BINFUNC_F_OPERATOR_SET( atan2, *180.0f/M_PI ); break;
     case GAL_ARITHMETIC_OP_COUNTS_TO_MAG:
       BINFUNC_F_OPERATOR_SET( gal_units_counts_to_mag, +0 ); break;
     case GAL_ARITHMETIC_OP_MAG_TO_COUNTS:
diff --git a/lib/units.c b/lib/units.c
index d310d78d..97be0d9c 100644
--- a/lib/units.c
+++ b/lib/units.c
@@ -6,6 +6,7 @@ Original author:
      Kartik Ohri <kartikohri13@gmail.com>
 Contributing author(s):
      Mohammad Akhlaghi <mohammad@akhlaghi.org>
+     Pedram Ashofteh Ardakani <pedramardakani@pm.me>
 Copyright (C) 2020-2022 Free Software Foundation, Inc.
 
 Gnuastro is free software: you can redistribute it and/or modify it
@@ -30,6 +31,8 @@ along with Gnuastro. If not, see 
<http://www.gnu.org/licenses/>.
 #include <stdlib.h>
 #include <string.h>
 
+#include <gsl/gsl_math.h>
+
 #include <gnuastro/type.h>
 #include <gnuastro/pointer.h>
 
@@ -409,12 +412,13 @@ gal_units_counts_to_jy(double counts, double zeropoint_ab)
 /**********************************************************************/
 /****************         Distance conversions        *****************/
 /**********************************************************************/
-/* Convert Astronomical Units (AU) to Parsecs (PC). From the definition
-   of Parsecs, 648000/pi AU = 1 PC. So   */
+/* Convert Astronomical Units (AU) to Parsecs (PC). From the definition of
+   Parsecs, 648000/pi AU = 1 PC. The mathematical constant 'PI' is imported
+   from the GSL as M_PI. So: */
 double
 gal_units_au_to_pc(double au)
 {
-  return au / 648000.0f * 3.14159265358979323846264338327f;
+  return au / 648000.0f * M_PI;
 }
 
 
@@ -426,7 +430,7 @@ gal_units_au_to_pc(double au)
 double
 gal_units_pc_to_au(double au)
 {
-  return au * 648000.0f / 3.14159265358979323846264338327f;
+  return au * 648000.0f / M_PI;
 }