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

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get_ipython().system('pip install imageio numpy matplotlib')
get_ipython().system('pip install -e .')


# In[2]:


from openpiv_python_lite import extended_search_area_piv as piv, get_coordinates, random_noise


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import numpy as np

frame_a = np.zeros((32, 32))
frame_a = random_noise(frame_a)
frame_b = np.roll(np.roll(frame_a, 3, axis=1), 2, axis=0)
threshold = 0.1

def test_piv_32():
    """ test of the simplest PIV run 32 x 32 """
    u, v = piv(frame_a, frame_b, window_size=32)
    assert(np.abs(u-3) < threshold)
    assert(np.abs(v+2) < threshold)


def test_piv_16_32():
    """ test of the search area larger than the window """
    u, v = piv(frame_a, frame_b, window_size=16, search_area_size=32)
    assert(np.abs(u[0,0]-3) < threshold)
    assert(np.abs(v[0,0]+2) < threshold)


# In[4]:


test_piv_32()


# In[5]:


test_piv_16_32()


# In[6]:


import imageio

def test_piv():
    """
    Simplest PIV run on the pair of images using default settings

    piv(im1,im2) will create a tmp.vec file with the vector filed in pix/dt (dt=1) from 
    two images, im1,im2 provided as full path filenames (TIF is preferable, whatever imageio can read)

    """


    # if im1 is None and im2 is None:
    im1 = ('./test/img/frame_a.tif')
    im2 = ('./test/img/frame_b.tif')

    frame_a = imageio.imread(im1)
    frame_b = imageio.imread(im2)
    
    frame_a[0:32, 512-32:] = 255

    print(frame_a[0,0])

    u, v = piv(frame_a,frame_b,
                                    window_size=32,overlap=16)
    x, y = get_coordinates(image_size = frame_a.shape, 
                           window_size=32, overlap=16)

    print(x[0], y[0], u[0], v[0])

    return x, y, u, v


# In[7]:


x,y,u,v = test_piv()


# In[8]:


import pylab


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pylab.quiver(x,y,u,-v)


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