pathsim.blocks.sources module

class pathsim.blocks.sources.Constant(value=1)

Bases: Block

Produces a constant output signal (SISO)

Parameters:

value (float) – constant defining block output

update(t)

update system equation fixed point loop

Parameters:

t (float) – evaluation time

Returns:

error – absolute error to previous iteration for convergence control (always ‘0.0’ because source-type)

Return type:

float

class pathsim.blocks.sources.Source(func=<function Source.<lambda>>)

Bases: Block

Source that produces an arbitrary time dependent output, defined by the func (callable).

\[y(t) = \mathrm{func}(t)\]

Note

This block is purely algebraic and its internal function (func) will be called multiple times per timestep, each time when Simulation._update(t) is called in the global simulation loop.

Example

For example a ramp:

from pathsim.blocks import Source

src = Source(lambda t : t)

or a simple sinusoid with some frequency:

import numpy as np
from pathsim.blocks import Source

#some parameter
omega = 100

#the function that gets evaluated
def f(t):
    return np.sin(omega * t)

src = Source(f)

Because the Source block only has a single argument, it can be used to decorate a function and make it a PathSim block. This might be handy in some cases to keep definitions concise and localized in the code:

import numpy as np
from pathsim.blocks import Source

#does the same as the definition above

@Source
def src(t):
    omega = 100
    return np.sin(omega * t)

#'src' is now a PathSim block

Parameters:

func (callable) – function defining time dependent block output

update(t)

update system equation fixed point loop by evaluating the internal function ‘func’

Note

No direct passthrough, so the update method is optimized and has no convergence check

Parameters:

t (float) – evaluation time

Returns:

error – absolute error to previous iteration for convergence control (always 0.0 because source-type)

Return type:

float