Regrouped everything in a single submodule.

Author: loiseaujc

src/stdlib_specialmatrices_symtridiagonal.fypp

@@ -15,6 +15,8 @@ submodule (stdlib_specialmatrices) tridiagonal_matrices
     !-----                      -----
     !--------------------------------
 
+    ! ----- Tridiagonal matrices -----
+
     #:for k1, t1, s1 in (KINDS_TYPES)
     pure module function initialize_tridiagonal_pure_${s1}$(dl, dv, du) result(A)
         !! Construct a `tridiagonal` matrix from the rank-1 arrays
@@ -137,6 +139,123 @@ submodule (stdlib_specialmatrices) tridiagonal_matrices
     end function
     #:endfor
 
+    !----- Symmetric Tridiagonal matrices -----
+
+    #:for k1, t1, s1 in (KINDS_TYPES)
+    pure module function initialize_symtridiagonal_pure_${s1}$(dv, ev) result(A)
+        !! Construct a `symtridiagonal` matrix from the rank-1 arrays
+        !! `dl`, `dv` and `du`.
+        ${t1}$, intent(in) :: dv(:), ev(:)
+        !! symtridiagonal matrix elements.
+        type(symtridiagonal_${s1}$_type) :: A
+        !! Corresponding symtridiagonal matrix.
+
+        ! Internal variables.
+        integer(ilp) :: n
+        type(linalg_state_type) :: err0
+
+        ! Sanity check.
+        n = size(dv, kind=ilp)
+        if (n <= 0) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Matrix size needs to be positive, n = ", n, ".")
+            call linalg_error_handling(err0)
+        endif
+        if (size(ev, kind=ilp) /= n-1) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Vector ev does not have the correct length.")
+            call linalg_error_handling(err0)
+        endif
+
+        ! Description of the matrix.
+        A%n = n
+        ! Matrix elements.
+        A%dl = ev ; A%dv = dv ; A%du = ev
+    end function
+
+    pure module function initialize_constant_symtridiagonal_pure_${s1}$(dv, ev, n) result(A)
+        !! Construct a `symtridiagonal` matrix with constant elements.
+        ${t1}$, intent(in) :: dv, ev
+        !! symtridiagonal matrix elements.
+        integer(ilp), intent(in) :: n
+        !! Matrix dimension.
+        type(symtridiagonal_${s1}$_type) :: A
+        !! Corresponding symtridiagonal matrix.
+
+        ! Internal variables.
+        integer(ilp) :: i
+        type(linalg_state_type) :: err0
+
+        ! Description of the matrix.
+        A%n = n
+        if (n <= 0) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Matrix size needs to be positive, n = ", n, ".")
+            call linalg_error_handling(err0)
+        endif
+        ! Matrix elements.
+        A%dl = [(ev, i = 1, n-1)]
+        A%dv = [(dv, i = 1, n-1)]
+        A%du = [(ev, i = 1, n-1)]
+    end function
+
+    module function initialize_symtridiagonal_impure_${s1}$(dv, ev, err) result(A)
+        !! Construct a `symtridiagonal` matrix from the rank-1 arrays
+        !! `dl`, `dv` and `du`.
+        ${t1}$, intent(in) :: dv(:), ev(:)
+        !! symtridiagonal matrix elements.
+        type(linalg_state_type), intent(out) :: err
+        !! Error handling.
+        type(symtridiagonal_${s1}$_type) :: A
+        !! Corresponding symtridiagonal matrix.
+
+        ! Internal variables.
+        integer(ilp) :: n
+        type(linalg_state_type) :: err0
+
+        ! Sanity check.
+        n = size(dv, kind=ilp)
+        if (n <= 0) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Matrix size needs to be positive, n = ", n, ".")
+            call linalg_error_handling(err0, err)
+        endif
+        if (size(ev, kind=ilp) /= n-1) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Vector ev does not have the correct length.")
+            call linalg_error_handling(err0, err)
+        endif
+
+        ! Description of the matrix.
+        A%n = n
+        ! Matrix elements.
+        A%dl = ev ; A%dv = dv ; A%du = ev
+    end function
+
+    module function initialize_constant_symtridiagonal_impure_${s1}$(dv, ev, n, err) result(A)
+        !! Construct a `symtridiagonal` matrix with constant elements.
+        ${t1}$, intent(in) :: dv, ev
+        !! symtridiagonal matrix elements.
+        integer(ilp), intent(in) :: n
+        !! Matrix dimension.
+        type(linalg_state_type), intent(out) :: err
+        !! Error handling
+        type(symtridiagonal_${s1}$_type) :: A
+        !! Corresponding symtridiagonal matrix.
+
+        ! Internal variables.
+        integer(ilp) :: i
+        type(linalg_state_type) :: err0
+
+        ! Description of the matrix.
+        A%n = n
+        if (n <= 0) then
+            err0 = linalg_state_type(this, LINALG_VALUE_ERROR, "Matrix size needs to be positive, n = ", n, ".")
+            call linalg_error_handling(err0, err)
+        endif
+        ! Matrix elements.
+        A%dl = [(ev, i = 1, n)]
+        A%dv = [(dv, i = 1, n-1)]
+        A%du = [(ev, i = 1, n)]
+    end function
+    #:endfor
+
+
     !-----------------------------------------
     !-----                               -----
     !-----     MATRIX-VECTOR PRODUCT     -----
@@ -294,7 +413,7 @@ submodule (stdlib_specialmatrices) tridiagonal_matrices
                 C = tridiagonal(A%dl, A%dv, A%du)
                 C%dl = C%dl + B%dl; C%dv = C%dv + B%dv; C%du = C%du + B%du
             type is(symtridiagonal_${s1}$_type)
-                ! SymTridiagonal + SymTridiagoanl = SymTridiagonal
+                ! SymTridiagonal + SymTridiagonal = SymTridiagonal
                 C = symtridiagonal(A%dv, A%du)
                 C%dl = C%dl + B%dl; C%dv = C%dv + B%dv; C%du = C%dl
             end select
@@ -318,7 +437,7 @@ submodule (stdlib_specialmatrices) tridiagonal_matrices
                 C = tridiagonal(A%dl, A%dv, A%du)
                 C%dl = C%dl - B%dl; C%dv = C%dv - B%dv; C%du = C%du - B%du    
             type is(symtridiagonal_${s1}$_type)
-                ! SymTridiagonal - SymTridiagoanl = SymTridiagonal
+                ! SymTridiagonal - SymTridiagonal = SymTridiagonal
                 C = symtridiagonal(A%dv, A%du)
                 C%dl = C%dl - B%dl; C%dv = C%dv - B%dv; C%du = C%dl
             end select