timeAdder.py

import openmdao.api as om
import numpy as np

class TimeAdder(om.ExplicitComponent):
    #This serves to keep track of the elapsed time. Since we performed a change of variables we need to integrate time by adding dt/ds

    def initialize(self):
        self.options.declare('num_nodes', types=int)

    def setup(self):
        nn = self.options['num_nodes']

        #states
        self.add_input('sdot', val=np.zeros(nn), desc='distance along track', units='m/s')

        #outputs
        self.add_output('dt_ds', val=np.zeros(nn), desc='distance perpendicular to centerline', units='s/m')


        self.declare_coloring(wrt='*', method='cs', tol=1.0E-12, show_sparsity=True)


    def compute(self, inputs, outputs):
        sdot = inputs['sdot']

        outputs['dt_ds'] = 1/sdot