add examples

Author: perazz

example/linalg/CMakeLists.txt

@@ -28,6 +28,8 @@ ADD_EXAMPLE(blas_gemv)
 ADD_EXAMPLE(lapack_getrf)
 ADD_EXAMPLE(lstsq1)
 ADD_EXAMPLE(lstsq2)
+ADD_EXAMPLE(norm)
+ADD_EXAMPLE(get_norm)
 ADD_EXAMPLE(solve1)
 ADD_EXAMPLE(solve2)
 ADD_EXAMPLE(solve3)

example/linalg/example_get_norm.f90

@@ -0,0 +1,51 @@
+! Vector norm: demonstrate usage of the function interface
+program example_get_norm
+  use stdlib_linalg, only: get_norm, linalg_state_type
+  implicit none
+  
+  real :: a(3,3),nrm,nrmd(3)
+  integer :: j
+  type(linalg_state_type) :: err
+    
+  ! a = [   -3.00000000   0.00000000   3.00000000
+  !         -2.00000000   1.00000000   4.00000000
+  !         -1.00000000   2.00000000   5.00000000   ]  
+  a = reshape([(j-4,j=1,9)], [3,3])
+  
+  print "(' a = [   ',3(g0,3x),2(/9x,3(g0,3x)),']')", transpose(a)
+    
+  ! Norm with integer input
+  call get_norm(a, nrm, 2)
+  print *, 'Euclidean norm      = ',nrm   ! 8.30662346
+  
+  ! Norm with character input
+  call get_norm(a, nrm, '2')
+  print *, 'Euclidean norm      = ',nrm   ! 8.30662346
+  
+  ! Euclidean norm of row arrays, a(i,:)
+  call get_norm(a, nrmd, 2, dim=2)
+  print *, 'Rows norms          = ',nrmd  ! 4.24264050       4.58257580       5.47722578  
+  
+  ! Euclidean norm of columns arrays, a(:,i)
+  call get_norm(a, nrmd, 2, dim=1)
+  print *, 'Columns norms       = ',nrmd  ! 3.74165750       2.23606801       7.07106781 
+  
+  ! Infinity norms
+  call get_norm(a, nrm, 'inf')
+  print *, 'maxval(||a||)       = ',nrm   ! 5.00000000
+  
+  call get_norm(a, nrmd, 'inf', dim=2)
+  print *, 'maxval(||a(i,:)||)  = ',nrmd  ! 3.00000000       4.00000000       5.00000000
+  
+  call get_norm(a, nrm, '-inf')
+  print *, 'minval(||a||)       = ',nrm   ! 0.00000000
+  
+  call get_norm(a, nrmd, '-inf', dim=1)
+  print *, 'minval(||a(:,i)||)  = ',nrmd  ! 1.00000000       0.00000000       3.00000000 
+  
+  ! Catch Error: 
+  ! [norm] returned Value Error: dimension 4 is out of rank for shape(a)= [3 3]
+  call get_norm(a, nrmd, 'inf', dim=4, err=err)
+  print *, 'invalid: ',err%print()  
+
+end program example_get_norm

example/linalg/example_norm.f90

@@ -0,0 +1,40 @@
+! Vector norm: demonstrate usage of the function interface
+program example_norm
+  use stdlib_linalg, only: norm, linalg_state_type
+  implicit none
+  
+  real :: a(3,3),na
+  integer :: j
+  type(linalg_state_type) :: err
+    
+  ! a = [   -3.00000000   0.00000000   3.00000000
+  !         -2.00000000   1.00000000   4.00000000
+  !         -1.00000000   2.00000000   5.00000000   ]  
+  a = reshape([(j-4,j=1,9)], [3,3])
+  
+  print "(' a = [   ',3(g0,3x),2(/9x,3(g0,3x)),']')", transpose(a)
+    
+  ! Norm with integer input
+  print *, 'Euclidean norm      = ',norm(a, 2)        ! 8.30662346
+  
+  ! Norm with character input
+  print *, 'Euclidean norm      = ',norm(a, '2')      ! 8.30662346
+  
+  ! Euclidean norm of row arrays, a(i,:)
+  print *, 'Rows norms          = ',norm(a, 2, dim=2) ! 4.24264050       4.58257580       5.47722578  
+  
+  ! Euclidean norm of columns arrays, a(:,i)
+  print *, 'Columns norms       = ',norm(a, 2, dim=1) ! 3.74165750       2.23606801       7.07106781 
+  
+  ! Infinity norms
+  print *, 'maxval(||a||)       = ',norm(a, 'inf')          ! 5.00000000
+  print *, 'maxval(||a(i,:)||)  = ',norm(a, 'inf', dim=2)   ! 3.00000000       4.00000000       5.00000000
+  print *, 'minval(||a||)       = ',norm(a, '-inf')         ! 0.00000000
+  print *, 'minval(||a(:,i)||)  = ',norm(a, '-inf', dim=1)  ! 1.00000000       0.00000000       3.00000000 
+  
+  ! Catch Error: 
+  ! [norm] returned Value Error: dimension 4 is out of rank for shape(a)= [3 3]
+  print *, 'invalid: ',norm(a,'inf', dim=4, err=err)
+  print *, 'error =  ',err%print()  
+
+end program example_norm