add test with random input

Author: perazz

test/linalg/test_linalg_lstsq.fypp

@@ -13,7 +13,6 @@ module test_linalg_least_squares
     public :: test_least_squares 
 
     contains
-    
 
     !> Solve sample least squares problems
     subroutine test_least_squares(tests)
@@ -24,15 +23,16 @@ module test_linalg_least_squares
 
         #:for rk,rt,ri in REAL_KINDS_TYPES
         #:if rk!="xdp"
-        tests = [tests,new_unittest("lease_squares_${ri}$",test_lstsq_one_${ri}$)]
+        tests = [tests,new_unittest("least_squares_${ri}$",test_lstsq_one_${ri}$), &
+                       new_unittest("least_squares_randm_${ri}$",test_lstsq_random_${ri}$)]
         #:endif
         #:endfor
 
     end subroutine test_least_squares
-
-    !> Simple polynomial fit
+    
     #:for rk,rt,ri in REAL_KINDS_TYPES
     #:if rk!="xdp"
+    !> Simple polynomial fit
     subroutine test_lstsq_one_${ri}$(error)
         type(error_type), allocatable, intent(out) :: error
 
@@ -64,6 +64,32 @@ module test_linalg_least_squares
 
     end subroutine test_lstsq_one_${ri}$
 
+    !> Fit from random array
+    subroutine test_lstsq_random_${ri}$(error)
+        type(error_type), allocatable, intent(out) :: error
+
+        type(linalg_state_type) :: state
+        integer(ilp), parameter :: n = 12, m = 3
+        ${rt}$ :: xsol(m),x(m),y(n),A(n,m)
+
+        ! Random coefficient matrix and solution
+        call random_number(A)
+        call random_number(xsol)
+        
+        ! Compute rhs
+        y = matmul(A,xsol)
+
+        ! Find polynomial
+        x = lstsq(A,y,err=state)
+
+        call check(error,state%ok(),state%print())
+        if (allocated(error)) return
+        
+        call check(error, all(abs(x-xsol)<1.0e-6_${rk}$), 'data converged')
+        if (allocated(error)) return
+        
+    end subroutine test_lstsq_random_${ri}$    
+    
     #:endif
     #:endfor