#!/usr/bin/env python
# coding: utf-8

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# test find_subpixel_position


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from pylab import *
get_ipython().run_line_magic('matplotlib', 'inline')


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from openpiv.pyprocess import find_first_peak, find_second_peak, find_subpixel_peak_position
from openpiv.pyprocess import extended_search_area_piv, correlate_windows
from scipy.ndimage import shift
from scipy.ndimage.filters import gaussian_filter


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from test_process import create_pair


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a = np.random.randn(32,32)
a = gaussian_filter(a,.5)

u0 = 2.8  # to the right
v0 = -5.3 # downwards

b = shift(a,(-v0, u0),mode='wrap')
plt.imshow(b)


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u,v = extended_search_area_piv(a,b,window_size=32)


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print(u-u0,v-v0)


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corr = correlate_windows(a,b)# + correlate_windows(c,d)
from scipy.ndimage.filters import gaussian_filter

corr = gaussian_filter(corr,1.5)

x,y = np.meshgrid(np.arange(corr.shape[0]),np.arange(corr.shape[1]))


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x1, y1, p1 = find_first_peak(corr)


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x2, y2, p2 = find_second_peak(corr)


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(i,j) = find_subpixel_peak_position(corr)


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from mpl_toolkits.mplot3d import Axes3D
fig = plt.figure(figsize=(10,10))
ax = fig.add_subplot(111, projection='3d')
ax.plot_surface(x,y,corr);
ax.scatter(j,i,p1,'o',color='r')


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x1,y1,p1,x2,y2,p2,i,j 


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32-i


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32-j


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