%matplotlib inline
Example performing a sensitivity analysis on a new model.
# Deriv prog model was selected because the model can be described as x' = x + dx*dt
from prog_models.models.thrown_object import ThrownObject
import numpy as np
def run_example():
# Demo model
# Step 1: Create instance of model
m = ThrownObject()
# Step 2: Setup for simulation
def future_load(t, x=None):
return m.InputContainer({})
# Step 3: Setup range on parameters considered
thrower_height_range = np.arange(1.2, 2.1, 0.1)
# Step 4: Sim for each
event = 'impact'
eods = np.empty(len(thrower_height_range))
for (i, thrower_height) in zip(range(len(thrower_height_range)), thrower_height_range):
m.parameters['thrower_height'] = thrower_height
simulated_results = m.simulate_to_threshold(future_load, threshold_keys=[event], dt =1e-3, save_freq =10)
eods[i] = simulated_results.times[-1]
# Step 5: Analysis
print('For a reasonable range of heights, impact time is between {} and {}'.format(round(eods[0],3), round(eods[-1],3)))
sensitivity = (eods[-1]-eods[0])/(thrower_height_range[-1] - thrower_height_range[0])
print(' - Average sensitivity: {} s per cm height'.format(round(sensitivity/100, 6)))
print(" - It seems impact time is not very sensitive to thrower's height")
# Now lets repeat for throw speed
throw_speed_range = np.arange(20, 40, 1)
eods = np.empty(len(throw_speed_range))
for (i, throw_speed) in zip(range(len(throw_speed_range)), throw_speed_range):
m.parameters['throwing_speed'] = throw_speed
simulated_results = m.simulate_to_threshold(future_load, threshold_keys=[event], options={'dt':1e-3, 'save_freq':10})
eods[i] = simulated_results.times[-1]
print('\nFor a reasonable range of throwing speeds, impact time is between {} and {}'.format(round(eods[0],3), round(eods[-1],3)))
sensitivity = (eods[-1]-eods[0])/(throw_speed_range[-1] - throw_speed_range[0])
print(' - Average sensitivity: {} s per m/s speed'.format(round(sensitivity/100, 6)))
print(" - It seems impact time is much more dependent on throwing speed")
# This allows the module to be executed directly
if __name__=='__main__':
run_example()