# Generated Code

The following is python code generated by the CellML API from this CellML file. (Back to language selection)

The raw code is available.

```# Size of variable arrays:
sizeAlgebraic = 0
sizeStates = 2
sizeConstants = 4
from math import *
from numpy import *

def createLegends():
legend_states = [""] * sizeStates
legend_rates = [""] * sizeStates
legend_algebraic = [""] * sizeAlgebraic
legend_voi = ""
legend_constants = [""] * sizeConstants
legend_voi = "t in component all (dimensionless)"
legend_states[0] = "x in component all (dimensionless)"
legend_states[1] = "y in component all (dimensionless)"
legend_constants[0] = "A in component all (dimensionless)"
legend_constants[1] = "B in component all (dimensionless)"
legend_constants[2] = "C in component all (dimensionless)"
legend_constants[3] = "D in component all (dimensionless)"
legend_rates[0] = "d/dt x in component all (dimensionless)"
legend_rates[1] = "d/dt y in component all (dimensionless)"
return (legend_states, legend_algebraic, legend_voi, legend_constants)

def initConsts():
constants = [0.0] * sizeConstants; states = [0.0] * sizeStates;
states[0] = 3
states[1] = 6
constants[0] = 1
constants[1] = 1
constants[2] = 1
constants[3] = 1
return (states, constants)

def computeRates(voi, states, constants):
rates = [0.0] * sizeStates; algebraic = [0.0] * sizeAlgebraic
rates[0] = constants[0]*states[0]-constants[1]*states[0]*states[1]
rates[1] = -constants[2]*states[1]+constants[3]*states[0]*states[1]
return(rates)

def computeAlgebraic(constants, states, voi):
algebraic = array([[0.0] * len(voi)] * sizeAlgebraic)
states = array(states)
voi = array(voi)
return algebraic

def solve_model():
"""Solve model with ODE solver"""
from scipy.integrate import ode
# Initialise constants and state variables
(init_states, constants) = initConsts()

# Set timespan to solve over
voi = linspace(0, 10, 500)

# Construct ODE object to solve
r = ode(computeRates)
r.set_integrator('vode', method='bdf', atol=1e-06, rtol=1e-06, max_step=1)
r.set_initial_value(init_states, voi[0])
r.set_f_params(constants)

# Solve model
states = array([[0.0] * len(voi)] * sizeStates)
states[:,0] = init_states
for (i,t) in enumerate(voi[1:]):
if r.successful():
r.integrate(t)
states[:,i+1] = r.y
else:
break

# Compute algebraic variables
algebraic = computeAlgebraic(constants, states, voi)
return (voi, states, algebraic)

def plot_model(voi, states, algebraic):
"""Plot variables against variable of integration"""
import pylab
(legend_states, legend_algebraic, legend_voi, legend_constants) = createLegends()
pylab.figure(1)
pylab.plot(voi,vstack((states,algebraic)).T)
pylab.xlabel(legend_voi)
pylab.legend(legend_states + legend_algebraic, loc='best')
pylab.show()

if __name__ == "__main__":
(voi, states, algebraic) = solve_model()
plot_model(voi, states, algebraic)
```
Source
Derived from workspace Lokta, Volterra at changeset 0fb9b0eb1a27.
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