refactor as per suggested changes

Author: gururaj1512

src/stdlib_stats_distribution_normal.fypp

@@ -33,9 +33,6 @@ module stdlib_stats_distribution_normal
 
         #:for k1, t1 in RC_KINDS_TYPES
             module procedure rvs_norm_array_${t1[0]}$${k1}$  !3 dummy variables
-        #:endfor
-
-        #:for k1, t1 in RC_KINDS_TYPES
             module procedure rvs_norm_array_default_${t1[0]}$${k1}$  !2 dummy variables (mold, array_size)
         #:endfor
     end interface rvs_normal
@@ -243,96 +240,55 @@ contains
     #:endfor
 
     #:for k1, t1 in REAL_KINDS_TYPES
-        impure function rvs_norm_array_default_${t1[0]}$${k1}$ (mold, array_size) result(res)
+        impure function rvs_norm_array_default_${t1[0]}$${k1}$ (array_size, mold) result(res)
             !
             ! Standard normal array random variate with default loc=0, scale=1
             ! The mold argument is used only to determine the type and is not referenced
             !
-            ${t1}$, intent(in) :: mold
             integer, intent(in) :: array_size
+            ${t1}$, intent(in) :: mold
             ${t1}$ :: res(array_size)
-            ${t1}$, parameter  ::  r = 3.442619855899_${k1}$, rr = 1.0_${k1}$/r
-            ${t1}$ ::  x, y, re
-            integer :: hz, iz, i
 
-            if (.not. zig_norm_initialized) call zigset
+            res = rvs_norm_array_${t1[0]}$${k1}$ (0.0_${k1}$, 1.0_${k1}$, array_size)
 
-            do i = 1, array_size
-                iz = 0
-                hz = dist_rand(1_int32)
-                iz = iand(hz, 127)
-                if (abs(hz) < kn(iz)) then
-                    re = hz*wn(iz)
-                else
-                    L1: do
-                        L2: if (iz == 0) then
-                            do
-                                x = -log(uni(1.0_${k1}$))*rr
-                                y = -log(uni(1.0_${k1}$))
-                                if (y + y >= x*x) exit
-                            end do
-                            re = r + x
-                            if (hz <= 0) re = -re
-                            exit L1
-                        end if L2
-                        x = hz*wn(iz)
-                        if (fn(iz) + uni(1.0_${k1}$)*(fn(iz - 1) - fn(iz)) < &
-                            exp(-HALF*x*x)) then
-                            re = x
-                            exit L1
-                        end if
-
-                        hz = dist_rand(1_int32)
-                        iz = iand(hz, 127)
-                        if (abs(hz) < kn(iz)) then
-                            re = hz*wn(iz)
-                            exit L1
-                        end if
-                    end do L1
-                end if
-                res(i) = re  ! Default: loc=0, scale=1, so re*1 + 0 = re
-            end do
         end function rvs_norm_array_default_${t1[0]}$${k1}$
 
     #:endfor
 
     #:for k1, t1 in CMPLX_KINDS_TYPES
-        impure function rvs_norm_array_default_${t1[0]}$${k1}$ (mold, array_size) result(res)
-            !
-            ! Standard normal complex array random variate with default loc=0, scale=1
-            ! The mold argument is used only to determine the type and is not referenced
-            !
-            ${t1}$, intent(in) :: mold
+        impure function rvs_norm_array_${t1[0]}$${k1}$ (loc, scale, array_size) result(res)
+            ${t1}$, intent(in) :: loc, scale
             integer, intent(in) :: array_size
             integer :: i
             ${t1}$ :: res(array_size)
             real(${k1}$) :: tr, ti
 
             do i = 1, array_size
-                tr = rvs_norm_0_r${k1}$ ()
-                ti = rvs_norm_0_r${k1}$ ()
+                tr = rvs_norm_r${k1}$ (loc%re, scale%re)
+                ti = rvs_norm_r${k1}$ (loc%im, scale%im)
                 res(i) = cmplx(tr, ti, kind=${k1}$)
             end do
 
-        end function rvs_norm_array_default_${t1[0]}$${k1}$
+        end function rvs_norm_array_${t1[0]}$${k1}$
 
     #:endfor
 
     #:for k1, t1 in CMPLX_KINDS_TYPES
-        impure function rvs_norm_array_${t1[0]}$${k1}$ (loc, scale, array_size) result(res)
-            ${t1}$, intent(in) :: loc, scale
+        impure function rvs_norm_array_default_${t1[0]}$${k1}$ (array_size, mold) result(res)
+            !
+            ! Standard normal complex array random variate with default loc=0, scale=1
+            ! The mold argument is used only to determine the type and is not referenced
+            !
             integer, intent(in) :: array_size
-            integer :: i
+            ${t1}$, intent(in) :: mold
             ${t1}$ :: res(array_size)
-            real(${k1}$) :: tr, ti
 
-            do i = 1, array_size
-                tr = rvs_norm_r${k1}$ (loc%re, scale%re)
-                ti = rvs_norm_r${k1}$ (loc%im, scale%im)
-                res(i) = cmplx(tr, ti, kind=${k1}$)
-            end do
+            ! Call the full procedure with default loc=(0,0), scale=(1,1)
+            res = rvs_norm_array_${t1[0]}$${k1}$ (cmplx(0.0_${k1}$, 0.0_${k1}$, kind=${k1}$), &
+                                                   cmplx(1.0_${k1}$, 1.0_${k1}$, kind=${k1}$), &
+                                                   array_size)
 
-        end function rvs_norm_array_${t1[0]}$${k1}$
+        end function rvs_norm_array_default_${t1[0]}$${k1}$
 
     #:endfor
 

test/stats/test_distribution_normal.fypp

@@ -170,7 +170,7 @@ contains
             mold = (0.0_${k1}$, 0.0_${k1}$)
         #:endif
 
-        a2 = nor_rvs(mold, 10)
+        a2 = nor_rvs(10, mold)
 
         call check(all(a1 == a2), msg="normal_distribution_rvs_default_${t1[0]}$${k1}$ failed", warn=warn)
     end subroutine test_nor_rvs_default_${t1[0]}$${k1}$