handle *GEES output

Author: perazz

src/stdlib_linalg_schur.fypp

@@ -11,24 +11,46 @@ submodule (stdlib_linalg) stdlib_linalg_schur
 
     contains
 
-    elemental subroutine handle_gees_info(info, m, sort, err)
-        integer(ilp), intent(in) :: info, m
-        logical, intent(in) :: sort
-        type(linalg_state_type), intent(out) :: err
+    !> Wrapper function to handle GEES error codes
+    elemental subroutine handle_gees_info(info, m, n, ldvs, err)
+        integer(ilp), intent(in) :: info, m, n, ldvs
+        type(linalg_state), intent(out) :: err
 
         ! Process GEES output
         select case (info)
-        case (0)
+        case (0_ilp)
             ! Success
-        case (-1)
-            err = linalg_state_type(this, LINALG_VALUE_ERROR, 'invalid matrix size m=', m)
-        case default
-            if (sort .and. info > 0) then
-                err = linalg_state_type(this, LINALG_INTERNAL_ERROR, 'sorting eigenvalues failed at index ', info)
+        case (-1_ilp)
+            ! Vector not wanted, but task is wrong
+            err = linalg_state(this, LINALG_INTERNAL_ERROR,'Invalid Schur vector task request')
+        case (-2_ilp)
+            ! Vector not wanted, but task is wrong
+            err = linalg_state(this, LINALG_INTERNAL_ERROR,'Invalid sorting task request')            
+        case (-4_ilp,-6_ilp)
+            ! Vector not wanted, but task is wrong
+            err = linalg_state(this, LINALG_VALUE_ERROR,'Invalid/non-square input matrix size:',[m,n])  
+        case (-11_ilp)
+            err = linalg_state(this, LINALG_VALUE_ERROR,'Schur vector matrix has insufficient size',[ldvs,n])
+        case (-13_ilp)
+            err = linalg_state(this, LINALG_INTERNAL_ERROR,'Insufficient working storage size')
+        case (1_ilp:)
+            
+            if (info==n+2) then 
+                err = linalg_state(this, LINALG_ERROR, 'Ill-conditioned problem: could not sort eigenvalues')
+            elseif (info==n+1) then 
+                err = linalg_state(this, LINALG_ERROR, 'Some selected eigenvalues lost property due to sorting')                
+            elseif (info==n) then 
+                err = linalg_state(this, LINALG_ERROR, 'Convergence failure: no converged eigenvalues')
             else
-                err = linalg_state_type(this, LINALG_INTERNAL_ERROR, 'GEES catastrophic error: info=', info)
+                err = linalg_state(this, LINALG_ERROR, 'Convergence failure; converged range is',[info,n])                            
             end if
+            
+        case default
+            
+            err = linalg_state(this, LINALG_INTERNAL_ERROR, 'GEES catastrophic error: info=', info)
+
         end select
+        
     end subroutine handle_gees_info
 
     #:for rk, rt, ri in RC_KINDS_TYPES