#########################################################################################

##

## AMPLIFIER BLOCK

## (blocks/amplifier.py)

##

#########################################################################################

# IMPORTS ===============================================================================

import numpy as np

from ._block import Block

from ..optim.operator import Operator

# SISO BLOCKS ===========================================================================

class Amplifier(Block):

"""Amplifies the input signal by multiplication with a constant gain term.

Like this:

.. math::

y(t) = \\mathrm{gain} \\cdot u(t)

Note

----

This block is purely algebraic and its operation (`op_alg`) will be called

multiple times per timestep, each time when `Simulation._update(t)` is

called in the global simulation loop.

Example

-------

The block is initialized like this:

.. code-block:: python

#amplification by factor 5

A = Amplifier(gain=5)

Parameters

----------

gain : float

amplifier gain

Attributes

----------

op_alg : Operator

internal algebraic operator

"""

def __init__(self, gain=1.0):

super().__init__()

self.gain = gain

self.op_alg = Operator(

func=lambda x: x*self.gain,

jac=lambda x: self.gain*np.eye(len(x))

)

def update(self, t):

"""update system equation in fixed point loop

Parameters

----------

t : float

evaluation time

"""

u = self.inputs.to_array()

y = self.op_alg(u)

self.outputs.update_from_array(y)