Add examples for deg2rad and rad2deg.

Author: MilanSkocic

example/math/CMakeLists.txt

@@ -12,5 +12,7 @@ ADD_EXAMPLE(math_arange)
 ADD_EXAMPLE(math_argd)
 ADD_EXAMPLE(math_arg)
 ADD_EXAMPLE(math_argpi)
+ADD_EXAMPLE(math_deg2rad)
+ADD_EXAMPLE(math_rad2deg)
 ADD_EXAMPLE(math_is_close)
 ADD_EXAMPLE(meshgrid)

example/math/example_math_deg2rad.f90

@@ -0,0 +1,8 @@
+program example_math_deg2rad
+    use stdlib_math, only: deg2rad
+    implicit none
+    print *, deg2rad(0.0)       ! 0.0
+    print *, deg2rad(90.0)      ! 1.57508
+    print *, deg2rad(-180.0)    ! -3.1416
+
+end program example_math_deg2rad

example/math/example_math_rad2deg.f90

@@ -0,0 +1,9 @@
+program example_math_rad2deg
+    use stdlib_math, only: rad2deg
+    use stdlib_constants, only: PI_sp
+    implicit none
+    print *, rad2deg(0.0)              ! 0.0
+    print *, rad2deg(PI_sp / 2.0)      ! 90.0
+    print *, rad2deg(-PI_sp)           ! -3.1416
+
+end program example_math_rad2deg