better make internal function

- not used
- no check whether matrix is positive-definite, i.e. danger of NaN

src/math.f90

@@ -961,12 +961,34 @@ subroutine math_eigh33(m,w,v)
 end subroutine math_eigh33
 
 
+
+
+!--------------------------------------------------------------------------------------------------
+!> @brief rotational part from polar decomposition of 3x3 tensor
+!--------------------------------------------------------------------------------------------------
+function math_rotationalPart(m)
+
+  real(pReal), intent(in), dimension(3,3) :: m
+  real(pReal), dimension(3,3) :: math_rotationalPart
+  real(pReal), dimension(3,3) :: U , Uinv
+
+  U = eigenvectorBasis(matmul(transpose(m),m))
+  Uinv = math_inv33(U)
+
+  inversionFailed: if (all(dEq0(Uinv))) then
+    math_rotationalPart = math_I3
+    call IO_warning(650)
+  else inversionFailed
+    math_rotationalPart = matmul(m,Uinv)
+  endif inversionFailed
+
+contains
   !--------------------------------------------------------------------------------------------------
   !> @brief eigenvector basis of positive-definite 3x3 matrix
   !--------------------------------------------------------------------------------------------------
-pure function math_eigenvectorBasisSym33(m)
+  pure function eigenvectorBasis(m)
 
-  real(pReal), dimension(3,3)             :: math_eigenvectorBasisSym33
+    real(pReal), dimension(3,3)             :: eigenvectorBasis
     real(pReal), dimension(3,3), intent(in) :: m                                                      !< positive-definite matrix of which the basis is computed
 
     real(pReal), dimension(3)               :: I, v
@@ -1015,31 +1037,11 @@ pure function math_eigenvectorBasisSym33(m)
       endif twoSimilarEigVals
     endif threeSimilarEigVals
 
- math_eigenvectorBasisSym33 = sqrt(v(1)) * EB(1:3,1:3,1) &
+   eigenvectorBasis = sqrt(v(1)) * EB(1:3,1:3,1) &
                     + sqrt(v(2)) * EB(1:3,1:3,2) &
                     + sqrt(v(3)) * EB(1:3,1:3,3)
 
-end function math_eigenvectorBasisSym33
+  end function eigenvectorBasis
-
-
-!--------------------------------------------------------------------------------------------------
-!> @brief rotational part from polar decomposition of 3x3 tensor
-!--------------------------------------------------------------------------------------------------
-function math_rotationalPart(m)
-
-  real(pReal), intent(in), dimension(3,3) :: m
-  real(pReal), dimension(3,3) :: math_rotationalPart
-  real(pReal), dimension(3,3) :: U , Uinv
-
-  U = math_eigenvectorBasisSym33(matmul(transpose(m),m))
-  Uinv = math_inv33(U)
-
-  inversionFailed: if (all(dEq0(Uinv))) then
-    math_rotationalPart = math_I3
-    call IO_warning(650)
-  else inversionFailed
-    math_rotationalPart = matmul(m,Uinv)
-  endif inversionFailed
 
 end function math_rotationalPart