lili/amodem
1
0
Fork 0
mirror of https://github.com/romanz/amodem.git synced 2026-03-20 01:06:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

dsp: move lfilter and IIR to tests

Browse Source
This commit is contained in:
Roman Zeyde
2015-02-11 17:20:51 +02:00
parent 4cebb06e11
commit d81ec630a5
5 changed files with 41 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
amodem/dsp.py
View File

@@ -18,32 +18,6 @@ class FIR(object):
self.x_state = x_
class IIR(object):
def __init__(self, b, a):
self.b = np.array(b) / a[0]
self.a = np.array(a[1:]) / a[0]
self.x_state = [0] * len(self.b)
self.y_state = [0] * (len(self.a) + 1)
def __call__(self, x):
x_, y_ = self.x_state, self.y_state
for v in x:
x_ = [v] + x_[:-1]
y_ = y_[:-1]
num = np.dot(x_, self.b)
den = np.dot(y_, self.a)
y = num - den
y_ = [y] + y_
yield y
self.x_state, self.y_state = x_, y_
def lfilter(b, a, x):
f = IIR(b=b, a=a)
y = list(f(x))
return np.array(y)
class Demux(object):
def __init__(self, sampler, omegas, Nsym):
self.Nsym = Nsym

5
tests/test_dsp.py
View File

@@ -1,6 +1,7 @@
from amodem import dsp
from amodem import sampling
from amodem import config
import utils
import numpy as np
import random
@@ -20,11 +21,11 @@ def test_linreg():
def test_filter():
x = range(10)
y = dsp.lfilter(b=[1], a=[1], x=x)
y = utils.lfilter(b=[1], a=[1], x=x)
assert (np.array(x) == y).all()
x = [1] + [0] * 10
y = dsp.lfilter(b=[0.5], a=[1, -0.5], x=x)
y = utils.lfilter(b=[0.5], a=[1, -0.5], x=x)
assert list(y) == [0.5 ** (i+1) for i in range(len(x))]

16
tests/test_equalizer.py
View File

@@ -2,7 +2,7 @@ from numpy.linalg import norm
from numpy.random import RandomState
import numpy as np
from amodem import dsp
import utils
from amodem import equalizer
from amodem import config
config = config.fastest()
@@ -24,14 +24,14 @@ def test_commutation():
x = np.random.RandomState(seed=0).normal(size=1000)
b = [1, 1j, -1, -1j]
a = [1, 0.1]
y = dsp.lfilter(x=x, b=b, a=a)
y1 = dsp.lfilter(x=dsp.lfilter(x=x, b=b, a=[1]), b=[1], a=a)
y2 = dsp.lfilter(x=dsp.lfilter(x=x, b=[1], a=a), b=b, a=[1])
y = utils.lfilter(x=x, b=b, a=a)
y1 = utils.lfilter(x=utils.lfilter(x=x, b=b, a=[1]), b=[1], a=a)
y2 = utils.lfilter(x=utils.lfilter(x=x, b=[1], a=a), b=b, a=[1])
assert_approx(y, y1)
assert_approx(y, y2)
z = dsp.lfilter(x=y, b=a, a=[1])
z_ = dsp.lfilter(x=x, b=b, a=[1])
z = utils.lfilter(x=y, b=a, a=[1])
z_ = utils.lfilter(x=x, b=b, a=[1])
assert_approx(z, z_)
@@ -50,7 +50,7 @@ def test_signal():
x = np.sign(RandomState(0).normal(size=length))
den = np.array([1, -0.6, 0.1])
num = np.array([0.5])
y = dsp.lfilter(x=x, b=num, a=den)
y = utils.lfilter(x=x, b=num, a=den)
lookahead = 2
h = equalizer.train(
@@ -60,5 +60,5 @@ def test_signal():
h = h[lookahead:]
assert_approx(h, den / num)
x_ = dsp.lfilter(x=y, b=h, a=[1])
x_ = utils.lfilter(x=y, b=h, a=[1])
assert_approx(x_, x)

6
tests/test_transfer.py
View File

@@ -1,8 +1,8 @@
from amodem import main
from amodem import common
from amodem import dsp
from amodem import sampling
from amodem import config
import utils
import numpy as np
import os
@@ -85,11 +85,11 @@ def test_timing(freq_err):
def test_lowpass():
run(1024, chan=lambda x: dsp.lfilter(b=[0.9], a=[1.0, -0.1], x=x))
run(1024, chan=lambda x: utils.lfilter(b=[0.9], a=[1.0, -0.1], x=x))
def test_highpass():
run(1024, chan=lambda x: dsp.lfilter(b=[0.9], a=[1.0, 0.1], x=x))
run(1024, chan=lambda x: utils.lfilter(b=[0.9], a=[1.0, 0.1], x=x))
def test_attenuation():

27
tests/utils.py Normal file
View File

@@ -0,0 +1,27 @@
import numpy as np
class IIR(object):
def __init__(self, b, a):
self.b = np.array(b) / a[0]
self.a = np.array(a[1:]) / a[0]
self.x_state = [0] * len(self.b)
self.y_state = [0] * (len(self.a) + 1)
def __call__(self, x):
x_, y_ = self.x_state, self.y_state
for v in x:
x_ = [v] + x_[:-1]
y_ = y_[:-1]
num = np.dot(x_, self.b)
den = np.dot(y_, self.a)
y = num - den
y_ = [y] + y_
yield y
self.x_state, self.y_state = x_, y_
def lfilter(b, a, x):
f = IIR(b=b, a=a)
y = list(f(x))
return np.array(y)