I have a data frame -> data with the shape (10000,257). I need to preprocess this dataframe so that I can use it in LSTM which requires a 3 dimensional input - (nrows,ntimesteps,nfeatures)I am working with the code snippet that is provided here:
def univariate_processing(variable, window):
import numpy as np
# create empty 2D matrix from variable
V = np.empty((len(variable)-window+1, window))
# take each row/time window
for i in range(V.shape[0]):
V[i,:] = variable[i : i+window]
V = V.astype(np.float32) # set common data type
return V
def RNN_regprep(df, y, len_input, len_pred): #, test_size):
# create 3D matrix for multivariate input
X = np.empty((df.shape[0]-len_input+1, len_input, df.shape[1]))
# Iterate univariate preprocessing on all variables - store them in XM
for i in range(df.shape[1]):
X[ : , : , i ] = univariate_processing(df[:,i], len_input)
# create 2D matrix of y sequences
y = y.reshape((-1,)) # reshape to 1D if needed
Y = univariate_processing(y, len_pred)
## Trim dataframes as explained
X = X[ :-(len_pred + 1) , : , : ]
Y = Y[len_input:-1 , :]
# Set common datatype
X = X.astype(np.float32)
Y = Y.astype(np.float32)
return X, Y
X,y = RNN_regprep(data,label, len_ipnut=200,len_pred=1)
While running this the following error is obtained:
numpy.core._exceptions._ArrayMemoryError: Unable to allocate 28.9 GiB for an array with shape (10000, 200, 257) and data type float64
I do understand that this is more of an issue with my memory within my server. I want to know any solution that I can change within my code to see if I can avoid this memory error or try reducing this memory consumption?
This is what windowed views are for. Using my recipe here:
var = np.random.rand(10000,257)
w = window_nd(var, 200, axis = 0)
Now you have a windowed view over var:
w.shape
Out[]: (9801, 200, 257)
But, importantly, it's using the exact same data as var, just looking into it in a windowed way:
w.__array_interface__['data'] #This is the memory's starting address
Out[]: (1448954720320, False)
var.__array_interface__['data']
Out[]: (1448954720320, False)
np.shares_memory(var, w)
Out[]: True
w.base.base.base is var #(lots of rearranging views in the background)
Out[]: True
So you can do:
def univariate_processing(variable, window):
return window_nd(variable, window, axis = 0)
That should significantly reduce your memory allocation, no "magic" required :)
You can also try
from skimage.util import view_as_windows
w = np.squeeze(view_as_windows(var, (200, 1)))
Which does almost the same thing. In this case: your answer would be:
def univariate_processing(variable, window):
from skimage.util import view_as_windows
window = (window,) + (1,)*(len(variable.shape)-1)
return np.squeeze(view_as_windows(variable, window))
I'm exploring neural networks, and I want to model some pictures with neural network. Picture is a function that maps pixel coordinates to color, so I make my network also with 2 input variables (x, y) and 1 (shade) to 3 (R, G, B) output coordinates. For example, like this:
import torch.nn as nn
net = nn.Sequential(
nn.Linear(2, 2),
nn.Sigmoid(),
nn.Linear(2, 1),
)
Now, I plot it like this:
import matplotlib.pyplot as plt
import numpy as np
def draw_image1(f):
image = []
y = 1
delta = 0.005
while y > 0:
x = 0
row = []
while x < 1:
row.append(f(x, y))
x += delta
image.append(row)
y -= delta
plt.imshow(image, extent=[0, 1, 0, 1], cmap='winter')
plt.draw()
draw_image1(lambda x, y: net(torch.Tensor([x, y])).item())
But it looks ugly and is slow because it uses Python lists instead of numpy arrays or tensors.
I have another version of code that draws images from functions, which looks better and is 100x faster:
def draw_image2(f):
x = np.linspace(0, 1, num = 200)
y = np.linspace(0, 1, num = 200)
X, Y = np.meshgrid(x, y)
image = f(X, Y)
plt.imshow(image, extent=[0, 1, 0, 1], cmap='winter')
plt.draw()
It works for functions that use numpy operations (like lambda x: x + y), but when I plug in my net in the same way as for previous function (draw_image2(lambda x, y: net(torch.Tensor([x, y])).item())), I get RuntimeError: mat1 and mat2 shapes cannot be multiplied (400x200 and 2x2), which I understand as my neural net complaining that it wants to be fed data in smaller pieces.
Is there any proper way to plot pytorch neural network output?
To feed a whole batch into nn.Linear(i, o), the input typically has the shape (b, i) where b is the size of the batch. If we take a look at the documentation you can actually use additional "batch"-dimensions in between. Actually since pytorch was primarily made for deep learning that is based on stochastic gradietn descent, pretty much all modules of pytorch require you to have at least one batch dimension.
So you could easily modify your second plotting function to something like:
import torch
import torch.nn as nn
import matplotlib.pyplot as plt
net = nn.Sequential(
nn.Linear(2, 2),
nn.Sigmoid(),
nn.Linear(2, 1),
)
def draw_image2(f):
device = torch.device('cpu') # or use your gpu alternatively
with torch.no_grad(): # disable building evaluation graph if you don't need it
x = torch.linspace(0, 1, 200)
y = torch.linspace(0, 1, 200)
X, Y = torch.meshgrid(x, y)
# the data dimension should be the last (2), as per documentation
inp = torch.stack([X, Y], dim=2).to(device) # shape = (200, 200, 2)
image = f(inp) # shape = (200, 200, 1)
image = image[..., 0].detach().cpu() # shape (200, 200)
plt.imshow(image, extent=[0, 1, 0, 1], cmap='winter')
plt.show()
return image
draw_image2(net)
Note that the with torch.no_grad() is not necessary for it to work, but it will save you some time. Depending on your network architecture it might also be worth to set your network to eval mode (net.eval()) first. Finally the .to(device)/.cpu() is also not necessary if you're not using your GPU.
I'm trying to detect lung cancer nodules using DICOM files. The main steps in cancer detection included following steps.
1) Preprocessing
* Converting the pixel values to Hounsfield Units (HU)
* Resampling to an isomorphic resolution to remove variance in scanner resolution
*Lung segmentation
2) Training the data set using preprocessed images in Tensorflow CNN
3) Testing and validation
I followed few online tutorials to do this.
I need to combine the given solutions in
1) https://www.kaggle.com/gzuidhof/full-preprocessing-tutorial
2) https://www.kaggle.com/sentdex/first-pass-through-data-w-3d-convnet.
I could implement the example in link two. But since it is lack ok lung segmentation and few other preprocessing steps I need to combine the steps in link one with link two. But I'm getting number of errors while doing it. Since I'm new to python can someone please help me in solving it.
There are 20 patient folders and each patient folder has number of slices, which are dicom files.
For the process_data method , slices_path of each patient and patient number was sent.
def process_data(slices,patient,labels_df,img_px_size,hm_slices):
try:
label=labels_df.get_value(patient,'cancer')
patient_pixels = get_pixels_hu(slices)
segmented_lungs2, spacing = resample(patient_pixels, slices, [1,1,1])
new_slices=[]
segmented_lung = segment_lung_mask(segmented_lungs2, False)
segmented_lungs_fill = segment_lung_mask(segmented_lungs2, True)
segmented_lungs=segmented_lungs_fill-segmented_lung
#This method returns smallest integer not less than x.
chunk_sizes =math.ceil(len(segmented_lungs)/HM_SLICES)
for slice_chunk in chunks(segmented_lungs,chunk_sizes):
slice_chunk=list(map(mean,zip(*slice_chunk))) #list - []
#print (slice_chunk)
new_slices.append(slice_chunk)
print(len(segmented_lungs), len(new_slices))
if len(new_slices)==HM_SLICES-1:
new_slices.append(new_slices[-1])
if len(new_slices)==HM_SLICES-2:
new_slices.append(new_slices[-1])
new_slices.append(new_slices[-1])
if len(new_slices)==HM_SLICES+2:
new_val =list(map(mean, zip(*[new_slices[HM_SLICES-1],new_slices[HM_SLICES],])))
del new_slices[HM_SLICES]
new_slices[HM_SLICES-1]=new_val
if len(new_slices)==HM_SLICES+1:
new_val =list(map(mean, zip(*[new_slices[HM_SLICES-1],new_slices[HM_SLICES],])))
del new_slices[HM_SLICES]
new_slices[HM_SLICES-1]=new_val
print('LENGTH ',len(segmented_lungs), len(new_slices))
except Exception as e:
# again, some patients are not labeled, but JIC we still want the error if something
# else is wrong with our code
print(str(e))
#print(len(new_slices))
if label==1: label=np.array([0,1])
elif label==0: label=np.array([1,0])
return np.array(new_slices),label
Main method
# Some constants
#data_dir = '../../CT_SCAN_IMAGE_SET/IMAGES/'
#patients = os.listdir(data_dir)
#labels_df=pd.read_csv('../../CT_SCAN_IMAGE_SET/stage1_labels.csv',index_col=0)
#patients.sort()
#print (labels_df.head())
much_data=[]
much_data2=[]
for num,patient in enumerate(patients):
if num%100==0:
print (num)
try:
slices = load_scan(data_dir + patients[num])
img_data,label=process_data(slices,patients[num],labels_df,IMG_PX_SIZE,HM_SLICES)
much_data.append([img_data,label])
#much_data2.append([processed,label])
except:
print ('This is unlabeled data')
np.save('muchdata-{}-{}-{}.npy'.format(IMG_PX_SIZE,IMG_PX_SIZE,HM_SLICES),much_data)
#np.save('muchdata-{}-{}-{}.npy'.format(IMG_PX_SIZE,IMG_PX_SIZE,HM_SLICES),much_data2)
The preprocessing part works fine but when I'm trying to enter the final out put to a Convolutional NN and train the data set , Following is the error I'm receiving including some of the comments that I had put
0
shape hu
(113, 512, 512)
Resize factor
[ 2.49557522 0.6015625 0.6015625 ]
shape
(282, 308, 308)
chunk size
15
282 19
LENGTH 282 20
Tensor("Placeholder:0", dtype=float32)
..........1.........
..........2.........
..........3.........
..........4.........
WARNING:tensorflow:From C:\Research\Python_installation\lib\site-packages\tensorflow\python\util\tf_should_use.py:170: initialize_all_variables (from tensorflow.python.ops.variables) is deprecated and will be removed after 2017-03-02.
Instructions for updating:
Use `tf.global_variables_initializer` instead.
..........5.........
..........6.........
Epoch 1 completed out of 20 loss: 0
..........7.........
Traceback (most recent call last):
File "C:\Research\LungCancerDetaction\sendbox2.py", line 436, in <module>
train_neural_network(x)
File "C:\Research\LungCancerDetaction\sendbox2.py", line 424, in train_neural_network
print('Accuracy:',accuracy.eval({x:[i[0] for i in validation_data], y:[i[1] for i in validation_data]}))
File "C:\Research\Python_installation\lib\site-packages\tensorflow\python\framework\ops.py", line 606, in eval
return _eval_using_default_session(self, feed_dict, self.graph, session)
File "C:\Research\Python_installation\lib\site-packages\tensorflow\python\framework\ops.py", line 3928, in _eval_using_default_session
return session.run(tensors, feed_dict)
File "C:\Research\Python_installation\lib\site-packages\tensorflow\python\client\session.py", line 789, in run
run_metadata_ptr)
File "C:\Research\Python_installation\lib\site-packages\tensorflow\python\client\session.py", line 968, in _run
np_val = np.asarray(subfeed_val, dtype=subfeed_dtype)
File "C:\Research\Python_installation\lib\site-packages\numpy\core\numeric.py", line 531, in asarray
return array(a, dtype, copy=False, order=order)
ValueError: could not broadcast input array from shape (20,310,310) into shape (20)
I think it is the issue with the 'segmented_lungs=segmented_lungs_fill-segmented_lung'
In the working example,
segmented_lungs=[cv2.resize(each_slice,(IMG_PX_SIZE,IMG_PX_SIZE)) for each_slice in patient_pixels]
Please help me in solving this. I'm unable to proceed since some time. If anything is not clear please let me know.
Following is the whole code that had tried.
import numpy as np # linear algebra
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)
import dicom
import os
import scipy.ndimage
import matplotlib.pyplot as plt
import cv2
import math
import tensorflow as tf
from skimage import measure, morphology
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
# Some constants
data_dir = '../../CT_SCAN_IMAGE_SET/IMAGES/'
patients = os.listdir(data_dir)
labels_df=pd.read_csv('../../CT_SCAN_IMAGE_SET/stage1_labels.csv',index_col=0)
patients.sort()
print (labels_df.head())
#Image pixel array watching
for patient in patients[:10]:
#label is to get the label of the patient. This is what done in the .get_value method.
label=labels_df.get_value(patient,'cancer')
path=data_dir+patient
slices = [dicom.read_file(path + '/' + s) for s in os.listdir(path)]
#You have dicom files and they have attributes.
slices.sort(key = lambda x: float(x.ImagePositionPatient[2]))
print (len(slices),slices[0].pixel_array.shape)
#If u need to see many slices and resize the large pixelated 2D images into 150*150 pixelated images
IMG_PX_SIZE=50
HM_SLICES=20
for patient in patients[:1]:
#label is to get the label of the patient. This is what done in the .get_value method.
label=labels_df.get_value(patient,'cancer')
path=data_dir+patient
slices = [dicom.read_file(path + '/' + s) for s in os.listdir(path)]
#You have dicom files and they have attributes.
slices.sort(key = lambda x: float(x.ImagePositionPatient[2]))
#This shows the pixel arrayed image related to the second slice of each patient
#subplot
fig=plt.figure()
for num,each_slice in enumerate(slices[:16]):
print (num)
y=fig.add_subplot(4,4,num+1)
#down sizing everything. Resize the imag size as their pixel values are 512*512
new_image=cv2.resize(np.array(each_slice.pixel_array),(IMG_PX_SIZE,IMG_PX_SIZE))
y.imshow(new_image)
plt.show()
print (len(patients))
###################################################################################
def get_pixels_hu(slices):
image = np.array([s.pixel_array for s in slices])
# Convert to int16 (from sometimes int16),
# should be possible as values should always be low enough (<32k)
image = image.astype(np.int16)
# Set outside-of-scan pixels to 0
# The intercept is usually -1024, so air is approximately 0
image[image == -2000] = 0
# Convert to Hounsfield units (HU)
for slice_number in range(len(slices)):
intercept = slices[slice_number].RescaleIntercept
slope = slices[slice_number].RescaleSlope
if slope != 1:
image[slice_number] = slope * image[slice_number].astype(np.float64)
image[slice_number] = image[slice_number].astype(np.int16)
image[slice_number] += np.int16(intercept)
return np.array(image, dtype=np.int16)
#The next problem is each patient is got different number of slices . This is a performance issue.
# Take the slices and put that into a list of slices and chunk that list of slices into fixed numer of
#chunk of slices and averaging those chunks.
#yield is like 'return'. It returns a generator
def chunks(l,n):
for i in range(0,len(l),n):
#print ('Inside yield')
#print (i)
yield l[i:i+n]
def mean(l):
return sum(l)/len(l)
def largest_label_volume(im, bg=-1):
vals, counts = np.unique(im, return_counts=True)
counts = counts[vals != bg]
vals = vals[vals != bg]
if len(counts) > 0:
return vals[np.argmax(counts)]
else:
return None
def segment_lung_mask(image, fill_lung_structures=True):
# not actually binary, but 1 and 2.
# 0 is treated as background, which we do not want
binary_image = np.array(image > -320, dtype=np.int8)+1
labels = measure.label(binary_image)
# Pick the pixel in the very corner to determine which label is air.
# Improvement: Pick multiple background labels from around the patient
# More resistant to "trays" on which the patient lays cutting the air
# around the person in half
background_label = labels[0,0,0]
#Fill the air around the person
binary_image[background_label == labels] = 2
# Method of filling the lung structures (that is superior to something like
# morphological closing)
if fill_lung_structures:
# For every slice we determine the largest solid structure
for i, axial_slice in enumerate(binary_image):
axial_slice = axial_slice - 1
labeling = measure.label(axial_slice)
l_max = largest_label_volume(labeling, bg=0)
if l_max is not None: #This slice contains some lung
binary_image[i][labeling != l_max] = 1
binary_image -= 1 #Make the image actual binary
binary_image = 1-binary_image # Invert it, lungs are now 1
# Remove other air pockets insided body
labels = measure.label(binary_image, background=0)
l_max = largest_label_volume(labels, bg=0)
if l_max is not None: # There are air pockets
binary_image[labels != l_max] = 0
return binary_image
#Loading the files
#Load the scans in given folder path
def load_scan(path):
slices = [dicom.read_file(path + '/' + s) for s in os.listdir(path)]
slices.sort(key = lambda x: float(x.ImagePositionPatient[2]))
try:
slice_thickness = np.abs(slices[0].ImagePositionPatient[2] - slices[1].ImagePositionPatient[2])
except:
slice_thickness = np.abs(slices[0].SliceLocation - slices[1].SliceLocation)
for s in slices:
s.SliceThickness = slice_thickness
return slices
def resample(image, scan, new_spacing=[1,1,1]):
# Determine current pixel spacing
spacing = np.array([scan[0].SliceThickness] + scan[0].PixelSpacing, dtype=np.float32)
resize_factor = spacing / new_spacing
new_real_shape = image.shape * resize_factor
new_shape = np.round(new_real_shape)
real_resize_factor = new_shape / image.shape
new_spacing = spacing / real_resize_factor
print ('Resize factor')
print (real_resize_factor)
image = scipy.ndimage.interpolation.zoom(image, real_resize_factor, mode='nearest')
print ('shape')
print (image.shape)
return image, new_spacing
'''def chunks(l,n):
for i in range(0,len(l),n):
#print ('Inside yield')
#print (i)
yield l[i:i+n]
def mean(l):
return sum(l)/len(l)'''
#processing data
def process_data(slices,patient,labels_df,img_px_size,hm_slices):
#for patient in patients[:10]:
#label is to get the label of the patient. This is what done in the .get_value method.
try:
label=labels_df.get_value(patient,'cancer')
print ('label process data')
print (label)
#path=data_dir+patient
#slices = [dicom.read_file(path + '/' + s) for s in os.listdir(path)]
#You have dicom files and they have attributes.
slices.sort(key = lambda x: float(x.ImagePositionPatient[2]))
#This shows the pixel arrayed image related to the second slice of each patient
patient_pixels = get_pixels_hu(slices)
print ('shape hu')
print (patient_pixels.shape)
segmented_lungs2, spacing = resample(patient_pixels, slices, [1,1,1])
#print ('Pix shape')
#print (segmented_lungs2.shape)
#segmented_lungs=np.array(segmented_lungs2).tolist()
new_slices=[]
segmented_lung = segment_lung_mask(segmented_lungs2, False)
segmented_lungs_fill = segment_lung_mask(segmented_lungs2, True)
segmented_lungs=segmented_lungs_fill-segmented_lung
#print ('length of segmented lungs')
#print (len(segmented_lungs))
#print ('Shape of segmented lungs......................................')
#print (segmented_lungs.shape)
#print ('hiiii')
#segmented_lungs=[cv2.resize(each_slice,(IMG_PX_SIZE,IMG_PX_SIZE)) for each_slice in segmented_lungs3]
#print ('bye')
#print ('length of slices')
#print (len(slices))
#print ('shape of slices')
#print (slices.shape)
#print (each_slice.pixel_array)
#This method returns smallest integer not less than x.
chunk_sizes =math.ceil(len(segmented_lungs)/HM_SLICES)
print ('chunk size ')
print (chunk_sizes)
for slice_chunk in chunks(segmented_lungs,chunk_sizes):
slice_chunk=list(map(mean,zip(*slice_chunk))) #list - []
#print (slice_chunk)
new_slices.append(slice_chunk)
print(len(segmented_lungs), len(new_slices))
if len(new_slices)==HM_SLICES-1:
new_slices.append(new_slices[-1])
if len(new_slices)==HM_SLICES-2:
new_slices.append(new_slices[-1])
new_slices.append(new_slices[-1])
if len(new_slices)==HM_SLICES-3:
new_slices.append(new_slices[-1])
new_slices.append(new_slices[-1])
new_slices.append(new_slices[-1])
if len(new_slices)==HM_SLICES+2:
new_val =list(map(mean, zip(*[new_slices[HM_SLICES-1],new_slices[HM_SLICES],])))
del new_slices[HM_SLICES]
new_slices[HM_SLICES-1]=new_val
if len(new_slices)==HM_SLICES+1:
new_val =list(map(mean, zip(*[new_slices[HM_SLICES-1],new_slices[HM_SLICES],])))
del new_slices[HM_SLICES]
new_slices[HM_SLICES-1]=new_val
if len(new_slices)==HM_SLICES+3:
new_val =list(map(mean, zip(*[new_slices[HM_SLICES-1],new_slices[HM_SLICES],])))
del new_slices[HM_SLICES]
new_slices[HM_SLICES-1]=new_val
print('LENGTH ',len(segmented_lungs), len(new_slices))
except Exception as e:
# again, some patients are not labeled, but JIC we still want the error if something
# else is wrong with our code
print(str(e))
#print(len(new_slices))
if label==1: label=np.array([0,1])
elif label==0: label=np.array([1,0])
return np.array(new_slices),label
# Some constants
#data_dir = '../../CT_SCAN_IMAGE_SET/IMAGES/'
#patients = os.listdir(data_dir)
#labels_df=pd.read_csv('../../CT_SCAN_IMAGE_SET/stage1_labels.csv',index_col=0)
#patients.sort()
#print (labels_df.head())
much_data=[]
much_data2=[]
for num,patient in enumerate(patients):
if num%100==0:
print (num)
try:
slices = load_scan(data_dir + patients[num])
img_data,label=process_data(slices,patients[num],labels_df,IMG_PX_SIZE,HM_SLICES)
much_data.append([img_data,label])
#much_data2.append([processed,label])
except:
print ('This is unlabeled data')
np.save('muchdata-{}-{}-{}.npy'.format(IMG_PX_SIZE,IMG_PX_SIZE,HM_SLICES),much_data)
#np.save('muchdata-{}-{}-{}.npy'.format(IMG_PX_SIZE,IMG_PX_SIZE,HM_SLICES),much_data2)
IMG_SIZE_PX = 50
SLICE_COUNT = 20
n_classes=2
batch_size=10
x = tf.placeholder('float')
y = tf.placeholder('float')
keep_rate = 0.8
def conv3d(x, W):
return tf.nn.conv3d(x, W, strides=[1,1,1,1,1], padding='SAME')
def maxpool3d(x):
# size of window movement of window as you slide about
return tf.nn.max_pool3d(x, ksize=[1,2,2,2,1], strides=[1,2,2,2,1], padding='SAME')
def convolutional_neural_network(x):
# # 5 x 5 x 5 patches, 1 channel, 32 features to compute.
weights = {'W_conv1':tf.Variable(tf.random_normal([3,3,3,1,32])),
# 5 x 5 x 5 patches, 32 channels, 64 features to compute.
'W_conv2':tf.Variable(tf.random_normal([3,3,3,32,64])),
# 64 features
'W_fc':tf.Variable(tf.random_normal([54080,1024])),
'out':tf.Variable(tf.random_normal([1024, n_classes]))}
biases = {'b_conv1':tf.Variable(tf.random_normal([32])),
'b_conv2':tf.Variable(tf.random_normal([64])),
'b_fc':tf.Variable(tf.random_normal([1024])),
'out':tf.Variable(tf.random_normal([n_classes]))}
# image X image Y image Z
x = tf.reshape(x, shape=[-1, IMG_SIZE_PX, IMG_SIZE_PX, SLICE_COUNT, 1])
conv1 = tf.nn.relu(conv3d(x, weights['W_conv1']) + biases['b_conv1'])
conv1 = maxpool3d(conv1)
conv2 = tf.nn.relu(conv3d(conv1, weights['W_conv2']) + biases['b_conv2'])
conv2 = maxpool3d(conv2)
fc = tf.reshape(conv2,[-1, 54080])
fc = tf.nn.relu(tf.matmul(fc, weights['W_fc'])+biases['b_fc'])
fc = tf.nn.dropout(fc, keep_rate)
output = tf.matmul(fc, weights['out'])+biases['out']
return output
much_data = np.load('muchdata-50-50-20.npy')
# If you are working with the basic sample data, use maybe 2 instead of 100 here... you don't have enough data to really do this
train_data = much_data[:-4]
validation_data = much_data[-4:]
def train_neural_network(x):
print ('..........1.........')
prediction = convolutional_neural_network(x)
print ('..........2.........')
#cost = tf.reduce_mean( tf.nn.softmax_cross_entropy_with_logits(prediction,y) )
cost = tf.reduce_mean( tf.nn.softmax_cross_entropy_with_logits(logits=prediction,labels=y))
print ('..........3.........')
optimizer = tf.train.AdamOptimizer(learning_rate=1e-3).minimize(cost)
print ('..........4.........')
hm_epochs = 20
with tf.Session() as sess:
sess.run(tf.initialize_all_variables())
successful_runs = 0
total_runs = 0
print ('..........5.........')
for epoch in range(hm_epochs):
epoch_loss = 0
for data in train_data:
total_runs += 1
try:
X = data[0]
Y = data[1]
_, c = sess.run([optimizer, cost], feed_dict={x: X, y: Y})
epoch_loss += c
successful_runs += 1
except Exception as e:
# I am passing for the sake of notebook space, but we are getting 1 shaping issue from one
# input tensor. Not sure why, will have to look into it. Guessing it's
# one of the depths that doesn't come to 20.
pass
#print(str(e))
print ('..........6.........')
print('Epoch', epoch+1, 'completed out of',hm_epochs,'loss:',epoch_loss)
print ('..........7.........')
correct = tf.equal(tf.argmax(prediction, 1), tf.argmax(y, 1))
accuracy = tf.reduce_mean(tf.cast(correct, 'float'))
print('Accuracy:',accuracy.eval({x:[i[0] for i in validation_data], y:[i[1] for i in validation_data]}))
print('Done. Finishing accuracy:')
print('Accuracy:',accuracy.eval({x:[i[0] for i in validation_data], y:[i[1] for i in validation_data]}))
print('fitment percent:',successful_runs/total_runs)
print (x)
# Run this locally:
train_neural_network(x)
P.S : resample() , segment_lung_mask() methods can be found from link 1.
For training you have
for data in train_data:
total_runs += 1
try:
X = data[0]
Y = data[1]
_, c = sess.run([optimizer, cost], feed_dict={x: X, y: Y})
So x and y are, respectively, the first two elements of a single row of train_data.
However, when calculating the accuracy you have
print('Accuracy:',accuracy.eval({x:[i[0] for i in validation_data], y:[i[1] for i in validation_data]}))
So x is the first element of all rows of validation_data, which gives it dimensions of (20,310,310), which can't be broadcast to a placeholder of dimension (20). Ditto for y. (Broadcasting means that if you gave it a tensor of dimensions (20, 310) it would know to take each of the 310 columns and feed it to the placeholder separately. It can't figure out what to do with a tensor of (20, 310, 310).)
Incidentally, when you declare your placeholders it's a good idea to specify their dimensions, using None for the dimension depending on the number of separate examples. This way the program can warn you when dimensions don't match up.
The error message seems to indicate that the placeholder tensors x and y have not been defined correctly. They should have the same shape as the input values X = data[0] and Y = data[1], such as
x = tf.placeholder(shape=[20,310,310], dtype=tf.float32)
# if y is a scalar:
y = tf.placeholder(shape=[], dtype=tf.float32)
I want to use scipy.signal.fftconvolve in Tensorflow/Keras, is there any way to do that?
Right now I am using the following code :
window = np.tile(window, (1, 1, 1, 3))
tf.nn.conv2d(img1, window, strides=[1,1,1,1], padding='VALID')
Are these lines equivalent to :
signal.fftconvolve(img1, window, mode='valid')
Implementation
FFT convolution can be relatively easily implemented in tensorflow. The following follows scipy.signal.fftconvolve quite strictly
import tensorflow as tf
def _centered(arr, newshape):
# Return the center newshape portion of the array.
currshape = tf.shape(arr)[-2:]
startind = (currshape - newshape) // 2
endind = startind + newshape
return arr[..., startind[0]:endind[0], startind[1]:endind[1]]
def fftconv(in1, in2, mode="full"):
# Reorder channels to come second (needed for fft)
in1 = tf.transpose(in1, perm=[0, 3, 1, 2])
in2 = tf.transpose(in2, perm=[0, 3, 1, 2])
# Extract shapes
s1 = tf.convert_to_tensor(tf.shape(in1)[-2:])
s2 = tf.convert_to_tensor(tf.shape(in2)[-2:])
shape = s1 + s2 - 1
# Compute convolution in fourier space
sp1 = tf.spectral.rfft2d(in1, shape)
sp2 = tf.spectral.rfft2d(in2, shape)
ret = tf.spectral.irfft2d(sp1 * sp2, shape)
# Crop according to mode
if mode == "full":
cropped = ret
elif mode == "same":
cropped = _centered(ret, s1)
elif mode == "valid":
cropped = _centered(ret, s1 - s2 + 1)
else:
raise ValueError("Acceptable mode flags are 'valid',"
" 'same', or 'full'.")
# Reorder channels to last
result = tf.transpose(cropped, perm=[0, 2, 3, 1])
return result
Example
A quick example of applying a gaussian smoothing with width 20 pixels to the standard "face" image is as follows:
if __name__ == '__main__':
from scipy import misc
import matplotlib.pyplot as plt
from tensorflow.python.ops import array_ops, math_ops
session = tf.InteractiveSession()
# Create gaussian
std = 20
grid_x, grid_y = array_ops.meshgrid(math_ops.range(3 * std),
math_ops.range(3 * std))
grid_x = tf.cast(grid_x[None, ..., None], 'float32')
grid_y = tf.cast(grid_y[None, ..., None], 'float32')
gaussian = tf.exp(-((grid_x - 1.5 * std) ** 2 + (grid_y - 1.5 * std) ** 2) / std ** 2)
gaussian = gaussian / tf.reduce_sum(gaussian)
face = misc.face(gray=False)[None, ...].astype('float32')
# Apply convolution
result = fftconv(face, gaussian, 'same')
result_r = session.run(result)
# Show results
plt.figure('face')
plt.imshow(face[0, ...] / 256.0)
plt.figure('convolved')
plt.imshow(result_r[0, ...] / 256.0)
You want just a regular conv2d then...
If you want it somewhere in the model, add a Conv2D(...,name='myLayer') layer, and in the model use model.get_layer('myLayer').set_weights([filters,biases])
If you want it in a loss function, just create a loss function:
import keras.backend as K
def myLoss(y_true, y_pred):
#where y_true is the true training data and y_pred is the model's output
convResult = K.conv2d(y_pred, kernel = window, padding = 'same')
anotherResult = K.depthwise_conv2d(y_pred, kernel = window, padding='same')
The regular conv2D will assume each output channel in the filter will process and sum all input channels.
The depthwise convolution will keep input channels separate.
Beware of the window, though. I don't know the format in tensorflow or scipy, but the kernel in keras should have this shape: (height, width, numberOfInputChannels, numberOfOutputChannels)
I believe, if I understand it right, it should be window = np.reshape(_FSpecialGauss(size, sigma), (size, size, 1, 1)), considering that "size" is the size of the kernel and you have only 1 input and output channels.
I used padding='same' to get the result image the same size of the input. If you use padding='valid', you will lose the borders (although in your case, your filter seems to have size (1,1), which won't remove borders).
You can use any tensorflow function inside the loss function as well:
def customLoss(yTrue,yPred):
tf.anyFunction(yTrue)
tf.anyFunction(yPred)
Using keras backend will let your code be portable to other backends later.
When compiling the model, give it your loss function:
model.compile(loss=myLoss, optimizer =....)
I am trying to produce a very easy example for combination of TensorArray and while_loop:
# 1000 sequence in the length of 100
matrix = tf.placeholder(tf.int32, shape=(100, 1000), name="input_matrix")
matrix_rows = tf.shape(matrix)[0]
ta = tf.TensorArray(tf.float32, size=matrix_rows)
ta = ta.unstack(matrix)
init_state = (0, ta)
condition = lambda i, _: i < n
body = lambda i, ta: (i + 1, ta.write(i,ta.read(i)*2))
# run the graph
with tf.Session() as sess:
(n, ta_final) = sess.run(tf.while_loop(condition, body, init_state),feed_dict={matrix: tf.ones(tf.float32, shape=(100,1000))})
print (ta_final.stack())
But I am getting the following error:
ValueError: Tensor("while/LoopCond:0", shape=(), dtype=bool) must be from the same graph as Tensor("Merge:0", shape=(), dtype=float32).
Anyone has on idea what is the problem?
There are several things in your code to point out. First, you don't need to unstack the matrix into the TensorArray to use it inside the loop, you can safely reference the matrix Tensor inside the body and index it using matrix[i] notation. Another issue is the different data type between your matrix (tf.int32) and the TensorArray (tf.float32), based on your code you're multiplying the matrix ints by 2 and writing the result into the array so it should be int32 as well. Finally, when you wish to read the final result of the loop, the correct operation is TensorArray.stack() which is what you need to run in your session.run call.
Here's a working example:
import numpy as np
import tensorflow as tf
# 1000 sequence in the length of 100
matrix = tf.placeholder(tf.int32, shape=(100, 1000), name="input_matrix")
matrix_rows = tf.shape(matrix)[0]
ta = tf.TensorArray(dtype=tf.int32, size=matrix_rows)
init_state = (0, ta)
condition = lambda i, _: i < matrix_rows
body = lambda i, ta: (i + 1, ta.write(i, matrix[i] * 2))
n, ta_final = tf.while_loop(condition, body, init_state)
# get the final result
ta_final_result = ta_final.stack()
# run the graph
with tf.Session() as sess:
# print the output of ta_final_result
print sess.run(ta_final_result, feed_dict={matrix: np.ones(shape=(100,1000), dtype=np.int32)})