From 004c4d47dc9b5cda334538b98f4611af720320dd Mon Sep 17 00:00:00 2001
From: "Mads M. Pedersen" <mmpe@dtu.dk>
Date: Wed, 29 Mar 2017 11:45:23 +0200
Subject: [PATCH] Adding missing modules
---
wetb/signal/__init__.py | 12 ++
wetb/signal/filters/__init__.py | 1 +
wetb/signal/filters/_differentiation.py | 37 ++++++
wetb/signal/filters/frq_filters.py | 144 ++++++++++++++++++++++++
wetb/signal/nan_replace.py | 22 ++++
5 files changed, 216 insertions(+)
create mode 100644 wetb/signal/__init__.py
create mode 100644 wetb/signal/filters/_differentiation.py
create mode 100644 wetb/signal/filters/frq_filters.py
create mode 100644 wetb/signal/nan_replace.py
diff --git a/wetb/signal/__init__.py b/wetb/signal/__init__.py
new file mode 100644
index 00000000..42d8da65
--- /dev/null
+++ b/wetb/signal/__init__.py
@@ -0,0 +1,12 @@
+
+d = None
+d = dir()
+
+from .interpolation import interpolate
+
+
+__all__ = [m for m in set(dir()) - set(d)]
+
+
+
+
diff --git a/wetb/signal/filters/__init__.py b/wetb/signal/filters/__init__.py
index 8de8c9ca..ebe5b72c 100644
--- a/wetb/signal/filters/__init__.py
+++ b/wetb/signal/filters/__init__.py
@@ -1 +1,2 @@
+from ._despike import *
from ._differentiation import *
\ No newline at end of file
diff --git a/wetb/signal/filters/_differentiation.py b/wetb/signal/filters/_differentiation.py
new file mode 100644
index 00000000..16caa027
--- /dev/null
+++ b/wetb/signal/filters/_differentiation.py
@@ -0,0 +1,37 @@
+'''
+Created on 29. mar. 2017
+
+@author: mmpe
+'''
+from wetb.signal.filters.frq_filters import low_pass
+import numpy as np
+def differentiation(x,sample_frq=None, cutoff_frq=None):
+ """Differentiate the signal
+
+ Parameters
+ ----------
+ x : array_like
+ The input signal
+ sample_frq : int, float or None, optional
+ sample frequency of signal (only required if low pass filer is applied)
+ cutoff_frq : int, float or None, optional
+ Low pass filter cut off (frequencies higher than this frequency will be suppressed)
+ Returns
+ -------
+ y : ndarray
+ differentiated signal
+
+
+ Examples
+ --------
+ >>> differentiation([1,2,1,0,1,1])
+ """
+
+
+ if cutoff_frq is not None:
+ assert sample_frq is not None, "Argument sample_frq must be set to apply low pass filter"
+ x = low_pass(x, sample_frq, cutoff_frq)
+ else:
+ x = np.array(x)
+ dy = np.r_[x[1]-x[0], (x[2:]-x[:-2])/2, x[-1]-x[-2]]
+ return dy
\ No newline at end of file
diff --git a/wetb/signal/filters/frq_filters.py b/wetb/signal/filters/frq_filters.py
new file mode 100644
index 00000000..58dec73c
--- /dev/null
+++ b/wetb/signal/filters/frq_filters.py
@@ -0,0 +1,144 @@
+'''
+Created on 27. mar. 2017
+
+@author: mmpe
+'''
+import numpy as np
+from scipy import signal
+
+def sine_generator(sample_frq, sine_frq, duration):
+ """Create a sine signal for filter test
+
+ Parameters
+ ----------
+ sample_frq : int, float
+ Sample frequency of returned signal [Hz]
+ sine_frq : int, float
+ Frequency of sine signal [Hz]
+ duration : int, float
+ Duration of returned signal [s]
+
+ Returns
+ -------
+ t,sig : ndarray, ndarray
+ time (t) and sine signal (sig)
+
+ Examples
+ --------
+ >>> sine_generator(10,1,2)
+ """
+ T = duration
+ nsamples = sample_frq * T
+ w = 2. * np.pi * sine_frq
+ t = np.linspace(0, T, nsamples, endpoint=False)
+ sig = np.sin(w * t)
+ return t, sig
+
+
+def low_pass(x, sample_frq, cutoff_frq, order=5):
+ """Low pass filter (butterworth)
+
+ Parameters
+ ----------
+ x : array_like
+ Input signal
+ sample_frq : int, float
+ Sample frequency [Hz]
+ cutoff_frq : int, float
+ Cut off frequency [Hz]
+ order : int
+ Order of the filter (1th order: 20db per decade, 2th order:)
+
+ Returns
+ -------
+ y : ndarray
+ Low pass filtered signal
+
+
+ Examples
+ --------
+ >>>
+ """
+ nyquist_frq = 0.5 * sample_frq
+ normal_cutoff = cutoff_frq / nyquist_frq
+ b,a = signal.butter(order, normal_cutoff, btype='low', analog=False)
+ return signal.filtfilt(b, a, x)
+
+def high_pass(x, sample_frq, cutoff_frq, order=5):
+ """Low pass filter (butterworth)
+
+ Parameters
+ ----------
+ x : array_like
+ Input signal
+ sample_frq : int, float
+ Sample frequency [Hz]
+ cutoff_frq : int, float
+ Cut off frequency [Hz]
+ order : int
+ Order of the filter (1th order: 20db per decade, 2th order:)
+
+ Returns
+ -------
+ y : ndarray
+ Low pass filtered signal
+
+
+ Examples
+ --------
+ >>>
+ """
+ nyquist_frq = 0.5 * sample_frq
+ normal_cutoff = cutoff_frq / nyquist_frq
+ b,a = signal.butter(order, normal_cutoff, btype='high', analog=False)
+ return signal.filtfilt(b, a, x)
+
+def frequency_response(sample_frq, cutoff_frq, type, order, plt=None):
+ """Frequency response of low/high pass filter (butterworth
+
+ Parameters
+ ----------
+ sample_frq : int, float
+ Sample frequency [Hz]
+ cutoff_frq : int, float
+ Cut off frequency [Hz]
+ type : {'low','high'}
+ Low or high pass filter
+ order : int
+ Order of the filter (1th order: 20db per decade, 2th order: 40db per decade)
+ plt : pyplot, optional
+ If specified, the frequency response is plotted
+
+ Returns
+ -------
+ w,h : ndarray, ndarray
+ Frequency (w) in Hz and filter response in db
+
+
+ Examples
+ --------
+ >>>
+ """
+ nyquist_frq = 0.5 * sample_frq
+ normal_cutoff = cutoff_frq / nyquist_frq
+ assert 0<normal_cutoff<1, "cutoff frequency must be <= nyquist frequency"
+ b,a = signal.butter(order, cutoff_frq, btype=type, analog=True)
+ w, h = signal.freqs(b, a)
+ h_db = 20 * np.log10(abs(h))
+ if plt:
+ plt.plot(w, h_db, label='%d order filter response'%order)
+
+ plt.legend(loc=0)
+
+ title = 'Butterworth filter frequency response'
+ if plt.axes().get_title()!=title:
+ plt.title(title)
+ plt.xlabel('Frequency [Hz]')
+ plt.ylabel('Amplitude [dB]')
+ plt.margins(.1, .1)
+ plt.xscale('log')
+
+ plt.grid(which='both', axis='both')
+ plt.axvline(cutoff_frq, color='green') # cutoff frequency
+
+ return w,h_db
\ No newline at end of file
diff --git a/wetb/signal/nan_replace.py b/wetb/signal/nan_replace.py
new file mode 100644
index 00000000..ffc691d0
--- /dev/null
+++ b/wetb/signal/nan_replace.py
@@ -0,0 +1,22 @@
+'''
+Created on 02/11/2015
+
+@author: MMPE
+'''
+
+import numpy as np
+from wetb.signal.filters import replacer
+def replace_by_mean(x):
+ return replacer.replace_by_mean(x, np.isnan(x))
+
+
+def replace_by_line(x):
+ return replacer.replace_by_line(x, np.isnan(x))
+
+def replace_by_polynomial(x, deg=3, no_base_points=12):
+ return replacer.replace_by_polynomial(x, np.isnan(x), deg, no_base_points)
+
+def max_no_nan(x):
+ return replacer.max_cont_mask_length(np.isnan(x))
+
+
--
GitLab