#! /usr/bin/env python3
#
def expm_ode ( x, y ):
  """
  expm_ode ( x, y ) evaluates the ODE right hand side dy/dx=-y+3*x

  Input:
    x is the independent variable
    y is the dependent variable
  Output:
    dydx is the value of dy/dx
  """
  dydx = - y - 3.0 * x
 
  return dydx

def expm_ode_test ( ):

  import numpy as np

  print ( "expm_ode_test:" )
  x = np.random.rand ( )
  y = np.random.rand ( )
  dydx = expm_ode ( x, y )

  print ( "x = ", x, "y = ", y, "dydx = ", dydx )

  return

if ( __name__ == "__main__" ):
  expm_ode_test ( )