Add example for expm

Author: loiseaujc

example/linalg/CMakeLists.txt

@@ -57,3 +57,4 @@ ADD_EXAMPLE(qr)
 ADD_EXAMPLE(qr_space)
 ADD_EXAMPLE(cholesky)
 ADD_EXAMPLE(chol)
+ADD_EXAMPLE(expm)

example/linalg/example_expm.f90

@@ -0,0 +1,7 @@
+program example_expm
+   use stdlib_linalg, only: expm
+   implicit none
+   real :: A(3, 3), E(3, 3)
+   A = reshape([1, 2, 3, 4, 5, 6, 7, 8, 9], [3, 3])
+   E = expm(A)
+end program example_expm