Official ARM version: v5.6.0HEADmaster

1 files changed, 79 insertions, 0 deletions

diff --git a/DSP/PythonWrapper/example.py b/DSP/PythonWrapper/example.py
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index 0000000..80fd87a
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+++ b/DSP/PythonWrapper/example.py
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+import cmsisdsp as dsp
+import numpy as np
+from scipy import signal
+from pylab import figure, clf, plot, xlabel, ylabel, xlim, ylim, title, grid, axes, show,semilogx, semilogy
+# Data file from https://www.physionet.org/pn3/ecgiddb/Person_87/rec_2.dat
+
+def q31sat(x):
+     if x > 0x7FFFFFFF:
+          return(np.int32(0x7FFFFFFF))
+     elif x < -0x80000000:
+          return(np.int32(0x80000000))
+     else:
+          return(np.int32(x))
+
+q31satV=np.vectorize(q31sat)
+
+def toQ31(x):
+     return(q31satV(np.round(x * (1<<31))))
+
+def Q31toF32(x):
+     return(1.0*x / 2**31)
+
+filename = 'rec_2.dat'
+
+f = open(filename,"r")
+sig = np.fromfile(f, dtype=np.int16)
+f.closed
+
+sig = 1.0*sig / (1 << 12)
+
+
+p0 = np.exp(1j*0.05) * 0.98 
+p1 = np.exp(1j*0.25) * 0.9 
+p2 = np.exp(1j*0.45) * 0.97
+
+z0 = np.exp(1j*0.02)
+z1 = np.exp(1j*0.65)
+z2 = np.exp(1j*1.0)
+
+g = 0.02
+
+nb = 300
+
+sos = signal.zpk2sos(
+      [z0,np.conj(z0),z1,np.conj(z1),z2,np.conj(z2)]
+     ,[p0, np.conj(p0),p1, np.conj(p1),p2, np.conj(p2)]
+     ,g)
+
+res=signal.sosfilt(sos,sig)
+figure()
+plot(sig[1:nb])
+figure()
+plot(res[1:nb])
+
+
+
+
+biquadQ31 = dsp.arm_biquad_casd_df1_inst_q31()
+numStages=3
+state=np.zeros(numStages*4)
+# For use in CMSIS, denominator coefs must be negated
+# and first a0 coef wihich is always 1 must be removed
+coefs=np.reshape(np.hstack((sos[:,:3],-sos[:,4:])),15)
+coefs = coefs / 4.0 
+coefsQ31 = toQ31(coefs)
+postshift = 2
+dsp.arm_biquad_cascade_df1_init_q31(biquadQ31,numStages,coefsQ31,state,postshift)
+sigQ31=toQ31(sig)
+nbSamples=sigQ31.shape[0]
+# Here we demonstrate how we can process a long sequence of samples per block
+# and thus check that the state of the biquad is well updated and preserved
+# between the calls.
+half = int(round(nbSamples / 2))
+res2a=dsp.arm_biquad_cascade_df1_q31(biquadQ31,sigQ31[1:half])
+res2b=dsp.arm_biquad_cascade_df1_q31(biquadQ31,sigQ31[half+1:nbSamples])
+res2=Q31toF32(np.hstack((res2a,res2b)))
+figure()
+plot(res2[1:nb])
+show()#
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