[gnuastro-commits] master 4068336 1/2: Library(arithmetic): new size operator for dataset's dimensions size

[Mohammad Akhlaghi]

branch: master
commit 4068336de5918c0c8223c0ec18ad6ad9a2ddbf5d
Author: Sachin Kumar Singh <address@hidden>
Commit: Sachin Kumar Singh <address@hidden>

    Library(arithmetic): new size operator for dataset's dimensions size
    
    The size operator prints the size of a dataset/HDU along a given
    dimension. This only needs the metadata to operate, which improves its
    efficiency.
---
 .gitignore                |  3 ++
 doc/gnuastro.texi         | 15 +++++++++
 lib/arithmetic.c          | 83 +++++++++++++++++++++++++++++++++++++++++++++++
 lib/gnuastro/arithmetic.h |  2 ++
 4 files changed, 103 insertions(+)

diff --git a/.gitignore b/.gitignore
index 5d38b96..c13ddaa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -160,3 +160,6 @@ bin/buildprog/astbuildprog.conf
 # directory, we have abandoned the convention above.
 
 /bootstrapped/build-aux
+
+# vscode
+.vscode/
diff --git a/doc/gnuastro.texi b/doc/gnuastro.texi
index aecf724..53b2a9e 100644
--- a/doc/gnuastro.texi
+++ b/doc/gnuastro.texi
@@ -10154,6 +10154,15 @@ For each pixel, find the sigma-clipped standard 
deviation in all given datasets.
 The output will have the a single-precision (32-bit) floating point type.
 This operator is called similar to the @command{sigclip-number} operator, 
please see there for more.
 
+@item size
+Size of the dataset along a given dimension. 
+The output will be a single unsigned integer(dimensions cannot be negative).
+For example, the following command will produce the dimension of the 
hdu1(default) in the first operand(a.fits) along the second axis.
+
+@example
+astarithmetic a.fits 2 size
+@end example
+
 @item filter-mean
 Apply mean filtering (or @url{https://en.wikipedia.org/wiki/Moving_average, 
moving average}) on the input dataset.
 During mean filtering, each pixel (data element) is replaced by the mean value 
of all its surrounding pixels (excluding blank values).
@@ -22265,6 +22274,12 @@ the termination criteria (see @ref{Sigma clipping}). 
The output type of
 for the rest it will be @code{GAL_TYPE_FLOAT32}.
 @end deffn
 
+@deffn Macro GAL_ARITHMETIC_OP_SIZE
+Size operator that will return a single value for datasets of any kind. When 
@code{gal_arithmetic} is called with this operator, it requires two arguments.
+The first is the dataset, and the second is a single integer value.
+The output type is a single integer.
+@end deffn
+
 @deffn Macro GAL_ARITHMETIC_OP_POW
 Binary operator to-power operator. When @code{gal_arithmetic} is called
 with any of these operators, it will expect two operands: raising the first
diff --git a/lib/arithmetic.c b/lib/arithmetic.c
index 9cb21e4..b759428 100644
--- a/lib/arithmetic.c
+++ b/lib/arithmetic.c
@@ -551,6 +551,77 @@ arithmetic_from_statistics(int operator, int flags, 
gal_data_t *input)
 
 
 /***********************************************************************/
+/***************                  Metadata                **************/
+/***********************************************************************/
+
+/* The size operator. Reports the size along a given dimension. */
+static gal_data_t *
+arithmetic_size(int operator, int flags, gal_data_t *in, gal_data_t *arg)
+{
+  gal_data_t *out=NULL;
+  size_t *out_arr;
+  size_t arg_val, temp_dsize=1;
+  size_t *dsize=&temp_dsize;
+
+  /* Check the type */
+  switch(arg->type)
+    {
+      case GAL_TYPE_FLOAT32:
+      case GAL_TYPE_FLOAT64:
+        error(EXIT_FAILURE, 0, "%s: size "
+              "operator can only work on integer types", __func__);
+    }
+
+  /* Convert `arg` to GAL_TYPE_SIZE_T */
+  arg=gal_data_copy_to_new_type_free(arg, GAL_TYPE_SIZE_T);
+
+  arg_val=*(size_t *)(arg->array);
+
+  /* Allocate size for the output data to make changes.
+     Set the output array value. */
+  dsize[0]=temp_dsize;
+  out=gal_data_alloc(NULL, GAL_TYPE_UINT64, 1, dsize,
+                    NULL, 0, in->minmapsize, 0,
+                    NULL, NULL, NULL);
+
+  out_arr=out->array;
+  out_arr[0]=in->dsize[arg_val-1];
+
+  /* The first argument must be a single integer. */
+  if(arg->size != 1)
+    {
+      /* If an image/array is passed, report error. */
+      error(EXIT_FAILURE, 0, "%s: first argument must be a single integer. ",
+            __func__);
+    }
+
+  /* Clean up and return */
+  if( flags & GAL_ARITHMETIC_FREE)
+    gal_data_free(in);
+
+  return out;
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+/***********************************************************************/
 /***************                  Where                   **************/
 /***********************************************************************/
 /* When the `iftrue' dataset only has one element and the element is blank,
@@ -1694,6 +1765,10 @@ gal_arithmetic_set_operator(char *string, size_t 
*num_operands)
   else if (!strcmp(string, "sigclip-std"))
     { op=GAL_ARITHMETIC_OP_SIGCLIP_STD;       *num_operands=-1; }
 
+  /* The size operator */
+  else if (!strcmp(string, "size"))
+    { op=GAL_ARITHMETIC_OP_SIZE;              *num_operands=2;  }
+
   /* Conditional operators. */
   else if (!strcmp(string, "lt" ))
     { op=GAL_ARITHMETIC_OP_LT;                *num_operands=2;  }
@@ -1821,6 +1896,8 @@ gal_arithmetic_operator_string(int operator)
     case GAL_ARITHMETIC_OP_SIGCLIP_MEAN:    return "sigclip-mean";
     case GAL_ARITHMETIC_OP_SIGCLIP_STD:     return "sigclip-number";
 
+    case GAL_ARITHMETIC_OP_SIZE:            return "size";
+
     case GAL_ARITHMETIC_OP_TO_UINT8:        return "uchar";
     case GAL_ARITHMETIC_OP_TO_INT8:         return "char";
     case GAL_ARITHMETIC_OP_TO_UINT16:       return "ushort";
@@ -1978,6 +2055,12 @@ gal_arithmetic(int operator, size_t numthreads, int 
flags, ...)
       out=arithmetic_change_type(d1, operator, flags);
       break;
 
+    /* Size operator */
+    case GAL_ARITHMETIC_OP_SIZE:
+      d1 = va_arg(va, gal_data_t *);
+      d2 = va_arg(va, gal_data_t *);
+      out=arithmetic_size(operator, flags, d1, d2);
+      break;
 
     /* When the operator is not recognized. */
     default:
diff --git a/lib/gnuastro/arithmetic.h b/lib/gnuastro/arithmetic.h
index b3c61eb..55fb624 100644
--- a/lib/gnuastro/arithmetic.h
+++ b/lib/gnuastro/arithmetic.h
@@ -127,6 +127,8 @@ enum gal_arithmetic_operators
   GAL_ARITHMETIC_OP_SIGCLIP_MEDIAN,/* Sigma-clipped median of mult. arrays.*/
   GAL_ARITHMETIC_OP_SIGCLIP_STD,  /* Sigma-clipped STD of multiple arrays. */
 
+  GAL_ARITHMETIC_OP_SIZE,         /* Size of the dataset along an axis     */
+
   GAL_ARITHMETIC_OP_TO_UINT8,     /* Convert to uint8_t.                   */
   GAL_ARITHMETIC_OP_TO_INT8,      /* Convert to int8_t.                    */
   GAL_ARITHMETIC_OP_TO_UINT16,    /* Convert to uint16_t.                  */