variance_dev:suggestions by @aradi

Author: jvdp1

src/common.fypp

@@ -97,6 +97,7 @@ ${prefix + joinstr.join([line.strip() for line in txt.split("\n")]) + suffix}$
   #:endif
 #:enddef
 
+
 #! Generates a routine name from a generic name, rank, type and kind
 #!
 #! Args:
@@ -113,33 +114,28 @@ ${prefix + joinstr.join([line.strip() for line in txt.split("\n")]) + suffix}$
   $:"{0}_{1}_{2}{3}_{2}{3}".format(gname, rank, type[0], kind) if suffix == '' else "{0}_{1}_{2}{3}_{4}".format(gname, rank, type[0], kind, suffix)
 #:enddef
 
-#! Generates Fortran expressions.
+
+#! Generates an array rank suffix for subarrays reducing the dimension
 #!
 #! Args:
-#!   varname (str): Name of the variable to be used as origin
-#!   varname1 (str): Name of the variable to be used instead of varname
-#!   origrank (int): Rank of the original variable
-#!   dim (int): Index of the used expression varname1
+#!   rank (int): Rank of the original variable
+#!   selectors (array): Dimension and name of the variable(s)
 #!
 #! Returns:
-#!   Shape expression enclosed in braces, except for the index dim.
-#!
-#! E.g., (:, :, :, i, :, :)
-#!
-
-#:def rankindice(varname, varname1, origrank, dim)
-  #:assert origrank > 0
-  #:if origrank > 0
-    #:call join_lines(joinstr=", ", prefix="(", suffix=")")
-      #:for i in range(1, origrank+1)
-        #:if i == dim
-          ${varname1}$
-        #:else
-          ${varname}$
-        #:endif
-      #:endfor
-    #:endcall
-  #:endif
+#!   Array rank suffix string enclosed in braces
+#!
+#! E.g.,
+#!   select_subarray(5 , [(4, 'i'), (5, 'j')])}$
+#!   -> (:, :, :, i, j)
+#!
+#:def select_subarray(rank, selectors)
+  #:assert rank > 0
+  #:set seldict = dict(selectors)
+  #:call join_lines(joinstr=", ", prefix="(", suffix=")")
+    #:for i in range(1, rank + 1)
+      $:seldict.get(i, ":")
+    #:endfor
+  #:endcall
 #:enddef
 
 #:endmute

src/stdlib_experimental_stats_var.fypp

@@ -91,9 +91,9 @@ contains
             mean = sum(x, dim) / n
             do i = 1, size(x, dim)
               #:if t1[0] == 'r'
-                res = res + (x${rankindice(':', 'i', rank, fi )}$ - mean)**2
+                res = res + (x${select_subarray(rank, [(fi, 'i')])}$ - mean)**2
               #:else
-                res = res + abs(x${rankindice(':', 'i', rank, fi )}$ - mean)**2
+                res = res + abs(x${select_subarray(rank, [(fi, 'i')])}$ - mean)**2
               #:endif
             end do
           #:endfor
@@ -132,7 +132,7 @@ contains
             n = real(size(x, dim), dp)
             mean = sum(real(x, dp), dim) / n
             do i = 1, size(x, dim)
-              res = res + (real(x${rankindice(':', 'i', rank, fi )}$, dp) - mean)**2
+              res = res + (real(x${select_subarray(rank, [(fi, 'i')])}$, dp) - mean)**2
             end do
           #:endfor
           case default
@@ -211,12 +211,12 @@ contains
             mean = sum(x, dim, mask) / n
             do i = 1, size(x, dim)
               #:if t1[0] == 'r'
-                res = res + merge( (x${rankindice(':', 'i', rank, fi )}$ - mean)**2,&
+                res = res + merge( (x${select_subarray(rank, [(fi, 'i')])}$ - mean)**2,&
               #:else
-                res = res + merge( abs(x${rankindice(':', 'i', rank, fi )}$ - mean)**2,&
+                res = res + merge( abs(x${select_subarray(rank, [(fi, 'i')])}$ - mean)**2,&
               #:endif
                                   0._${k1}$,&
-                                  mask${rankindice(':', 'i', rank, fi)}$)
+                                  mask${select_subarray(rank, [(fi, 'i')])}$)
             end do
           #:endfor
           case default
@@ -249,8 +249,8 @@ contains
             n = real(count(mask, dim), dp)
             mean = sum(real(x, dp), dim, mask) / n
             do i = 1, size(x, dim)
-              res = res + merge((real(x${rankindice(':', 'i', rank, fi )}$, dp) - mean)**2,&
-                                  0._dp, mask${rankindice(':', 'i', rank, fi)}$)
+              res = res + merge((real(x${select_subarray(rank, [(fi, 'i')])}$, dp) - mean)**2,&
+                                  0._dp, mask${select_subarray(rank, [(fi, 'i')])}$)
             end do
           #:endfor
           case default