Convergence issues in 2D RBF Neuron implemented as a Keras layer - keras

We implemented a 2D Gaussian radial basis layer (RBF) in Keras and are running into convergence issues with batch sizes larger than 1. The Neuron should implement the following function:
f(x,y)=exp(-a((x-x_0)²+(y-y_0)²)
Here x_0, y_0 and a are fit parameters.
Testcase
Currently we are doing correctness tests and are trying to fit just a single Neuron on the 2D function above. The Neuron should be (and is in case of batch_size 1) able to approximate this function exactly. The optimal loss is 0.
Problem
If we choose a batch size of 1 in this code, the prediction with Keras will converge very often and will be nearly independent of the starting parameters.
If we increase the batch size, the fit might produce a random walk, freeze or not converge at all. In all of these cases (even batch_size 2) convergence is a lot worse than in the batch_size 1 case. If we choose the batch_size as the size of the trainingset (i.e. 1296, our desired batch size), the fit will freeze most of the time mostly independent of learning rate.
Code
We implemented this layer in the following code:
# 2D RBF Layer
# In case anybody wants to use this code afterwards:
# Licenses: Apache, MIT, BSD, LGPLv2 and v3 and Public Domain
# Input: x,y Pairs, shape: (2,)
# Output: exp(a* ((x-x_0)**2 + (y-y_0)**2)), shape: (1,)
# Parameters: x_0, y_0, a - called: mean_x, mean_y and opening in the following code:
# x and y should both lie in [0,1] - only [0,infinity] is enforced currently
class RBFLayer2D(Layer):
def __init__(self, **kwargs):
super(RBFLayer2D, self).__init__(**kwargs)
def build(self, input_shape):
# Create a trainable weight variable for this layer.
self.mean_x = K.variable(0.35)
self.constraints[self.mean_x] = NonNeg()
self.mean_y = K.variable(0.35)
self.constraints[self.mean_y] = NonNeg()
self.opening = K.variable(2.0)
self.constraints[self.opening] = NonNeg()
self.trainable_weights = [self.mean_x,self.mean_y,self.opening]
super(RBFLayer2D, self).build(input_shape) # Be sure to call this somewhere!
def call(self, x):
x_m = x[:,0] - self.mean_x
y_m = x[:,1] - self.mean_y
out = x_m*x_m + y_m*y_m
outexp = 50.0*K.exp(-64.8*self.opening*out)
# Output: exp(-a* ((x-x_0)**2 + (y-y_0)**2))
return outexp
def compute_output_shape(self, input_shape):
# If Inputshape is (None, N) Outputshape is (None,N/2)
# In our example we only look at (None, 2), which outputs (None,1)
output_shape = (input_shape[0], input_shape[1]//2)
return output_shape
Reproduction
To reproduce set a batch_size of 1 in the (not-so) minimal example after this section. When you run it, the code will display the target distribution (a circle in the lower left corner), the starting guess for our RBF ANN (a smaller circler in the middle) and then after each iteration the current guess (a circle getting bigger and moving to the lower left corner).
Afterwards set a batch_size of 12 and restart the code and you will not observe convergence anymore.
Minimal Example
from __future__ import print_function
from __future__ import division
import numpy as np
np.random.seed(1234)
import matplotlib.pyplot as plt
from keras.engine import Layer
from keras.optimizers import SGD
from keras.models import Sequential
from keras.constraints import NonNeg
from keras import backend as K
# 2D RBF Layer
# Input: x,y Pairs, shape: (2,)
# Output: exp(a* ((x-x_0)**2 + (y-y_0)**2)), shape: (1,)
# Parameters: x_0, y_0, a - called: mean_x, mean_y and opening in the following code:
# x and y should both lie in [0,1] - only [0,infinity] is enforced currently
class RBFLayer2D(Layer):
def __init__(self, **kwargs):
super(RBFLayer2D, self).__init__(**kwargs)
def build(self, input_shape):
# Create a trainable weight variable for this layer.
self.mean_x = K.variable(0.35)
self.constraints[self.mean_x] = NonNeg()
self.mean_y = K.variable(0.35)
self.constraints[self.mean_y] = NonNeg()
self.opening = K.variable(2.0)
self.constraints[self.opening] = NonNeg()
self.trainable_weights = [self.mean_x,self.mean_y,self.opening]
super(RBFLayer2D, self).build(input_shape)
def call(self, x):
x_m = x[:,0] - self.mean_x
y_m = x[:,1] - self.mean_y
out = x_m*x_m + y_m*y_m
outexp = 50.0*K.exp(-64.8*self.opening*out)
# Output: exp(-a* ((x-x_0)**2 + (y-y_0)**2))
return outexp
def compute_output_shape(self, input_shape):
# If Inputshape is (None, N) Outputshape is (None,N/2)
# In our example we only look at (None, 2), which outputs (None,1)
output_shape = (input_shape[0], input_shape[1]//2)
return output_shape
# The function we want to train.
# It can be exactly represented using a single Neuron.
def twodenergy(phi, psi):
r0 = np.array([-180, -180])
b = 0.00005
return 50.0 * np.exp(- b * ((phi - r0[0]) ** 2 + (psi - r0[1]) ** 2))
# One of two plotting helper functions to show the results
def make_plot(y,numsteps,numbins,minangle,maxangle,plotnum, batch_size):
evaluation = np.zeros((numsteps, numsteps))
for i in range(0, numbins):
mx = i % numsteps
my = int(i / numsteps)
evaluation[mx,my]=y[i]
plt.imshow(evaluation.T, origin='lower',extent=[minangle, maxangle, minangle, maxangle])
plt.xlabel("x")
plt.ylabel("y")
if plotnum == 0:
plt.title("Startconfiguration")
else:
plt.title("RBF for batch_size %i at frame %03d" % (batch_size, plotnum))
plt.show()
# One of two plotting helper functions to show the target function
def plot_target_function(phi, psi, minangle, maxangle, delta_angle_half, numbins, numsteps ):
eval_matrix_corr = np.zeros((numsteps, numsteps))
for i in range(0, numbins):
mx = i % numsteps
my = int(i / numsteps)
ph = phi[mx] +delta_angle_half
ps = psi[my] +delta_angle_half
eval_matrix_corr[mx,my] = twodenergy(ph,ps)
plt.imshow(eval_matrix_corr.T, origin='lower', extent=[minangle, maxangle, minangle, maxangle])
plt.title("Target Function")
plt.xlabel("phi")
plt.ylabel("psi")
plt.show()
if __name__ == "__main__":
# batch_size == 1: converges very often nearly independent of input parameters
# batch_size == 2: no to slow convergence, but distribution stays in the right place more or less
# batch_size == 3-12: random walk
# batch_size == 1296: no movement in case of low learning_rate, random_walk in case of high learning_rate
# (this is the case where the whole map is evaluated in every step.
# 1296 is our desired testcase, because it evaluates the whole map we want to fit.
batch_size = 1
learning_rate = 1E-5
### Here we generate the target function ###
### f(phi,psi)
### phi is [-180,180]
### psi is [-180,180]
anglestep = 10.0
minangle = -180.0
maxangle = 180.0
numsteps = int((maxangle - minangle)/anglestep)
anglerange = maxangle - minangle
numbins = numsteps*numsteps
delta_angle_half = anglerange /(2.0* numsteps)
phi = np.arange(minangle, maxangle, anglestep)
psi = np.arange(minangle, maxangle, anglestep)
#Target Function Plot, Gaussian in lower left
plot_target_function(phi, psi, minangle, maxangle, delta_angle_half, numbins, numsteps )
# Input Parameter Regularization
# we map -180..180 to 0..1
# we also calculate the training parameters for our x,y pairs:
x_train = np.zeros((numbins, 2))
y_train = np.zeros((numbins, 1))
for x,ph in enumerate(phi):
for y,ps in enumerate(psi):
myphi = (ph + delta_angle_half - minangle)/(anglerange)
mypsi = (ps + delta_angle_half- minangle)/(anglerange)
x_train[x * numsteps + y, 0] = (ph +delta_angle_half - minangle)/(anglerange)
x_train[x * numsteps + y, 1] = (ps + delta_angle_half- minangle)/(anglerange)
y_train[x * numsteps + y] = twodenergy(ph +delta_angle_half,ps +delta_angle_half)
# Prediction with Keras
model = Sequential()
# Single RBF Layer, only one node
model.add(RBFLayer2D(input_shape=(2,)))
sgd = SGD(lr=learning_rate)
model.compile(loss="mean_squared_error", optimizer=sgd)
# We plot the starting configuration.
y = model.predict(x_train, batch_size=batch_size)
make_plot(y, numsteps, numbins, minangle, maxangle, 0, batch_size)
#Plot the first 15 iterations:
for i in range(0,15):
# For demonstration purposes, we fit 1 epoch and plot the output.
model.fit(x_train,y_train, epochs=1, batch_size=batch_size)
y = model.predict(x_train, batch_size=batch_size)
make_plot(y, numsteps, numbins, minangle, maxangle, 1 + i, batch_size)

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To replicate the idea in pytorch, my training loop looks like this:
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....
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first = 0
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minimizer.zero_grad()
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...
This seems to work but is there a more elegant/efficient way to achieve the same thing? Also - not sure I know where the best place to put the minimizer.zero_grad()
Thanks

Nested optimization in pytorch

I wrote a short snippet to train a classification model, and learn the learning rate of its optimization algorithm. In my example I tried to update weights of a network in an inner optimization loop and to learn the learning rate of the weight updates using an outer optimization loop (meta-optimization). I'm getting the error:
RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation: [torch.FloatTensor [3, 10]], which is output 0 of AsStridedBackward0, is at version 12; expected version 2 instead. Hint: enable anomaly detection to find the operation that failed to compute its gradient, with torch.autograd.set_detect_anomaly(True).
My code snippet is as following (NOTE: I'm using _stateless, an experimental functional API for nn. You need to run with the nightly build of pytorch.)
import torch
from torch import nn, optim
from torch.utils.data import Dataset, DataLoader
from torch.nn.utils import _stateless
class MyDataset(Dataset):
def __init__(self, N):
self.N = N
self.x = torch.rand(self.N, 10)
self.y = torch.randint(0, 3, (self.N,))
def __len__(self):
return self.N
def __getitem__(self, idx):
return self.x[idx], self.y[idx]
class MyModel(nn.Module):
def __init__(self):
super(MyModel, self).__init__()
self.fc1 = nn.Linear(10, 10)
self.fc2 = nn.Linear(10, 3)
self.relu = nn.ReLU()
self.alpha = nn.Parameter(torch.randn(1))
self.beta = nn.Parameter(torch.randn(1))
def forward(self, x):
y = self.relu(self.fc1(x))
return self.fc2(y)
epochs = 20
N = 100
dataset = DataLoader(dataset=MyDataset(N), batch_size=10)
model = MyModel()
loss_func = nn.CrossEntropyLoss()
optim = optim.Adam([model.alpha], lr=1e-3)
params = dict(model.named_parameters())
for i in range(epochs):
model.train()
train_loss = 0
for batch_idx, (x, y) in enumerate(dataset):
logits = _stateless.functional_call(model, params, x) # predict
loss_inner = loss_func(logits, y) # loss
optim.zero_grad() # reset grad
loss_inner.backward(create_graph=True, inputs=params.values()) # compute grad
train_loss += loss_inner.item() # store loss
for k, p in params.items():
if k is not 'alpha' and k is not 'beta':
p.update = - model.alpha * p.grad
params[k] = p + p.update # update weight
print('Train Epoch: {}\tLoss: {:.6f}'.format(i, train_loss / N))
logits = _stateless.functional_call(model, params, x) # predict
loss_meta = loss_func(logits, y)
loss_meta.backward()
loss_meta.step()
From the error message, I understand that the issue comes from weight update for the weights of the second layer of the network, which points to an error in my inner loop optimization. Any suggestions would be appreciated.
Check this link and save PARAMs per each epoch and use same inner batch:
https://discuss.pytorch.org/t/issue-using-parameters-internal-method/134549/11
for i in range(epochs):
model.train()
train_loss = 0
params = dict(model.named_parameters()) # add this
for batch_idx, (x, y) in enumerate(dataset):
params = {k: v.clone() for k,v in params.items()} # add this
logits = _stateless.functional_call(model, params, x) # predict
loss_inner = loss_func(logits, y)
..................
You should be updating params[k].data instead of params[k]
(Deleted the example to avoid distraction)
Let me enter in a kind of fundamental discussion (not an answer to your question).
If I undertand correctly you want to compute loss(f(w[i], x)) , and computing the w[i+1,j] = w[i,j] + g(v[j], w[i,j].grad(w.r.t loss)) . Then in the end you want to compute v[j+1] = v[j] + v[j].grad(w.r.t loss).
The gradient of v[j] is computed using the backward propagation, as a function of grad w[i,j]. So what you are trying to do is to choose v[j] that results in a good w[i,j]. I would ask: why would you bother about v[j] if you can control w[i,j] directly? And that's what the standard approach.

How to use Tensorflow to compute per-sample gradient and reduce them with an arbitrary function?

Given a (mini-)batch of size M, I want to acquire M gradients (one for each sample) and reduce them to a single gradient with an arbitrary function (instead of the typical mean). Then, I want to use this last gradient to train the network with.
I have the example below which somewhat works. The problem is that not only it gets slower and slower as iterations go by, but also the programs keeps on using more and more memory. As far as I can tell, this happens because I'm adding new operations to Tensorflow's computational graph on each iteration, but I lack the knowledge of Tensorflow to avoid doing this and still achieve my objective.
import sys
import numpy as np
import tensorflow as tf
# Import MNIST data
from tensorflow.examples.tutorials.mnist import input_data
mnist = input_data.read_data_sets("/tmp/data/", one_hot=True)
# Parameters
learning_rate = 0.0001
n_iterations = 1000000
batch_size = 2
display_step = 1000
# Network Parameters
n_hidden_1 = 256
n_hidden_2 = 256
n_input = 784
n_output = 10
# Create model
def build_network(x, weights, biases):
assert sys.version_info[:2] >= (3,6) # otherwise iteration on dict is ill-defined
layer = x
for (w_str,w),(b_str,b) in zip(weights.items(), biases.items()):
print(w_str,b_str)
layer = tf.add(tf.matmul(layer, w), b)
return layer
def max_gradient(gradients):
assert len(gradients) >= 1
# compute the resulting gradient, by choosing the (abs) max component wise
tgv = gradients[0]
for gv in gradients[1:]:
for (tg,tv),(g,v) in zip(tgv,gv):
assert (tv == v).all()
np.copyto(tg,g,where=abs(g) > abs(tg))
return tgv
def main(sess):
# tf Graph input/output
X = tf.placeholder('float', [None, n_input])
Y = tf.placeholder('float', [None, n_output])
# Store layers weight & bias
weights = {
'h1': tf.Variable(tf.random_normal([n_input, n_hidden_1])),
'h2': tf.Variable(tf.random_normal([n_hidden_1, n_hidden_2])),
'out': tf.Variable(tf.random_normal([n_hidden_2, n_output]))
}
biases = {
'b1': tf.Variable(tf.random_normal([n_hidden_1])),
'b2': tf.Variable(tf.random_normal([n_hidden_2])),
'out': tf.Variable(tf.random_normal([n_output]))
}
# Construct model
model = build_network(X, weights, biases)
# Loss
loss_op = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=model, labels=Y))
# Optimizer
opt = tf.train.GradientDescentOptimizer(learning_rate=learning_rate)
# Gradient
gv_op = opt.compute_gradients(loss_op)
# Trainable variables
t_vars = tf.trainable_variables()
# Initializing the variables
sess.run(tf.global_variables_initializer())
# Training cycle
for i in range(n_iterations):
# Get new training data
X_train, Y_train = mnist.train.next_batch(batch_size)
# Run the cost operation (to get the loss value)
c = sess.run(loss_op, feed_dict={X: X_train, Y: Y_train})
print(i, c)
# get the gradients for each batch sample
gradients = [sess.run(gv_op,
feed_dict={X: X_train[[j]], Y: Y_train[[j]]})
for j in range(batch_size)]
# compute the resulting gradient
tgv = max_gradient(gradients)
# assert that all the variables match
for (_,v1),v2 in zip(tgv,t_vars):
assert (v1 == sess.run(v2)).all()
# place the actual variables for the variable slots
tgv = [(g,v) for (g,_),v in zip(tgv, t_vars)]
# apply the transformation
sess.run(opt.apply_gradients(tgv))
if __name__ == '__main__':
with tf.Session() as sess:
main(sess)
How can I compute per-sample gradient and reduce them with an arbitrary function without constantly adding new operations to Tensorflow's graph?

Visualization of the filters of VGG16

I am learning CNN, right now, working on deconvolution of the layers. I have begun the process of learning upsampling and observe how convolution layers see the world by generating feature maps from the filters from the source Visualization of the filters of VGG16, with the Source code. I have changed the input and the code is as follows:
import imageio
import numpy as np
import time
from keras.applications import vgg16
from keras import backend as K
import cv2
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
# dimensions of the generated pictures for each filter.
img_width = 128
img_height = 128
# the name of the layer we want to visualize
# (see model definition at keras/applications/vgg16.py)
layer_name = 'block5_conv1'
# util function to convert a tensor into a valid image
def deprocess_image(x):
# normalize tensor: center on 0., ensure std is 0.1
x -= x.mean()
x /= (x.std() + K.epsilon())
x *= 0.1
# clip to [0, 1]
x += 0.5
x = np.clip(x, 0, 1)
# convert to RGB array
x *= 255
if K.image_data_format() == 'channels_first':
x = x.transpose((1, 2, 0))
x = np.clip(x, 0, 255).astype('uint8')
return x
# build the VGG16 network with ImageNet weights
model = vgg16.VGG16(weights='imagenet', include_top=False)
print('Model loaded.')
model.summary()
# this is the placeholder for the input images
input_img = model.input
# get the symbolic outputs of each "key" layer (we gave them unique names).
layer_dict = dict([(layer.name, layer) for layer in model.layers[1:]])
def normalize(x):
# utility function to normalize a tensor by its L2 norm
return x / (K.sqrt(K.mean(K.square(x))) + K.epsilon())
kept_filters = []
for filter_index in range(200):
# we only scan through the first 200 filters,
# but there are actually 512 of them
print('Processing filter %d' % filter_index)
start_time = time.time()
# we build a loss function that maximizes the activation
# of the nth filter of the layer considered
layer_output = layer_dict[layer_name].output
if K.image_data_format() == 'channels_first':
loss = K.mean(layer_output[:, filter_index, :, :])
else:
loss = K.mean(layer_output[:, :, :, filter_index])
# we compute the gradient of the input picture wrt this loss
grads = K.gradients(loss, input_img)[0]
# normalization trick: we normalize the gradient
grads = normalize(grads)
# this function returns the loss and grads given the input picture
iterate = K.function([input_img], [loss, grads])
# step size for gradient ascent
step = 1.
inpImgg = '/home/sanaalamgeer/Downloads/cat.jpeg'
inpImg = mpimg.imread(inpImgg)
inpImg = cv2.resize(inpImg, (img_width, img_height))
# we start from a gray image with some random noise
if K.image_data_format() == 'channels_first':
input_img_data = inpImg.reshape((1, 3, img_width, img_height))
else:
input_img_data = inpImg.reshape((1, img_width, img_height, 3))
input_img_data = (input_img_data - 0.5) * 20 + 128
# we run gradient ascent for 20 steps
for i in range(20):
loss_value, grads_value = iterate([input_img_data])
input_img_data += grads_value * step
print('Current loss value:', loss_value)
if loss_value <= 0.:
# some filters get stuck to 0, we can skip them
break
# decode the resulting input image
if loss_value > 0:
img = deprocess_image(input_img_data[0])
kept_filters.append((img, loss_value))
end_time = time.time()
print('Filter %d processed in %ds' % (filter_index, end_time - start_time))
# we will stich the best 64 filters on a 8 x 8 grid.
n = 8
# the filters that have the highest loss are assumed to be better-looking.
# we will only keep the top 64 filters.
kept_filters.sort(key=lambda x: x[1], reverse=True)
kept_filters = kept_filters[:n * n]
# build a black picture with enough space for
# our 8 x 8 filters of size 128 x 128, with a 5px margin in between
margin = 5
width = n * img_width + (n - 1) * margin
height = n * img_height + (n - 1) * margin
stitched_filters = np.zeros((width, height, 3))
# fill the picture with our saved filters
for i in range(n):
for j in range(n):
img, loss = kept_filters[i * n + j]
stitched_filters[(img_width + margin) * i: (img_width + margin) * i + img_width,
(img_height + margin) * j: (img_height + margin) * j + img_height, :] = img
# save the result to disk
imageio.imwrite('stitched_filters_%dx%d.png' % (n, n), stitched_filters)
The input image I am using is
It is supposed to generate an output with 64 feature maps embedded into one image as shown in Visualization of the filters of VGG16, but it is generating the same input image at each filter,
.
I am confused what's wrong or where I should make changes.
Please help.
What a complex code....
I'd do this:
from keras.applications.vgg16 import preprocess_input
layer_name = 'block5_conv1'
#create a section of the model to output the layer we want
model = vgg16.VGG16(weights='imagenet', include_top=False)
model = Model(model.input, model.get_layer(layer_name).output)
#open and preprocess the cat image
catImage = openTheCatImage(catFile)
catImage = np.expand_dims(catImage,axis=0)
catImage = preprocess_input(catImage)
#get the layer outputs
features = model.predict(catImage)
#plot
for channel in range(features.shape[-1]): #or .shape[1], or up to a limit you like
featureMap = features[:,:,:,channel] #or features[:,channel]
featureMap = deprocess_image(feature_map)[0]
saveOrPlot(featureMap)

How do I obtain predictions and probabilities from new data input to a CNN in Tensorflow

I'll preface this by saying this is my first posted question on SO. I've just recently started working with Tensorflow, and have been attempting to apply a convolutional-neural network model approach for classification of .csv records in a file representing images from scans of microarray data. (FYI: Microarrays are a grid of spotted DNA on a glass slide, representing specific DNA target sequences for determining the presence of those DNA targets in a sample. The individual pixels represent fluorescence intensity value from 0-1). The file has ~200,000 records in total. Each record (image) has 10816 pixels that represent DNA sequences from known viruses, and one index label which identifies the virus species. The pixels create a pattern which is unique to each of the different viruses. There are 2165 different viruses in total represented within the 200,000 records. I have trained the network on images of labeled microarray datasets, but when I try to pass a new dataset through to classify it/them as one of the 2165 different viruses and determine predicted values and probabilities, I don't seem to be having much luck. This is the code that I am currently using for this:
import tensorflow as tf
import numpy as np
import csv
def extract_data(filename):
print("extracting data...")
NUM_LABELS = 2165
NUM_FEATURES = 10816
labels = []
fvecs = []
rowCount = 0
#iterate over the rows, split the label from the features
#convert the labels to integers and features to floats
for line in open(filename):
rowCount = rowCount + 1
row = line.split(',')
labels.append(row[3])#(int(row[7])) #<<<IT ALWAYS PREDICTS THIS VALUE!
for x in row [4:10820]:
fvecs.append(float(x))
#convert the array of float arrasy into a numpy float matrix
fvecs_np = np.matrix(fvecs).astype(np.float32)
#convert the array of int lables inta a numpy array
labels_np = np.array(labels).astype(dtype=np.uint8)
#convert the int numpy array into a one-hot matrix
labels_onehot = (np.arange(NUM_LABELS) == labels_np[:, None]).astype(np.float32)
print("arrays converted")
return fvecs_np, labels_onehot
def TestModels():
fvecs_np, labels_onehot = extract_data("MicroarrayTestData.csv")
print('RESTORING NN MODEL')
weights = {}
biases = {}
sess=tf.Session()
init = tf.global_variables_initializer()
#Load meta graph and restore weights
ModelID = "MicroarrayCNN_Data-1000.meta"
print("RESTORING:::", ModelID)
saver = tf.train.import_meta_graph(ModelID)
saver.restore(sess,tf.train.latest_checkpoint('./'))
graph = tf.get_default_graph()
x = graph.get_tensor_by_name("x:0")
y = graph.get_tensor_by_name("y:0")
keep_prob = tf.placeholder(tf.float32)
y_ = tf.placeholder("float", shape=[None, 2165])
wc1 = graph.get_tensor_by_name("wc1:0")
wc2 = graph.get_tensor_by_name("wc2:0")
wd1 = graph.get_tensor_by_name("wd1:0")
Wout = graph.get_tensor_by_name("Wout:0")
bc1 = graph.get_tensor_by_name("bc1:0")
bc2 = graph.get_tensor_by_name("bc2:0")
bd1 = graph.get_tensor_by_name("bd1:0")
Bout = graph.get_tensor_by_name("Bout:0")
weights = {wc1, wc2, wd1, Wout}
biases = {bc1, bc2, bd1, Bout}
print("NEXTArgmax")
prediction=tf.argmax(y,1)
probabilities = y
predY = prediction.eval(feed_dict={x: fvecs_np, y: labels_onehot}, session=sess)
probY = probabilities.eval(feed_dict={x: fvecs_np, y: labels_onehot}, session=sess)
accuracy = tf.reduce_mean(tf.cast(prediction, "float"))
print(sess.run(accuracy, feed_dict={x: fvecs_np, y: labels_onehot}))
print("%%%%%%%%%%%%%%%%%%%%%%%%%%")
print("Predicted::: ", predY, accuracy)
print("%%%%%%%%%%%%%%%%%%%%%%%%%%")
feed_dictTEST = {y: labels_onehot}
probabilities=probY
print("probabilities", probabilities.eval(feed_dict={x: fvecs_np}, session=sess))
########## Run Analysis ###########
TestModels()
So, when I run this code I get the correct prediction for the test set, although I am not sure I believe it, because it appears that whatever value I append in line 14 (see below) is the output it predicts:
labels.append(row[3])#<<<IT ALWAYS PREDICTS THIS VALUE!
I don't understand this, and it makes me suspicious that I've set up the CNN incorrectly, as I would have expected it to ignore my input label and determine a bast match from the trained network based on the trained patterns. The only thing I can figure is that when I pass the value through for the prediction; it is instead training the model on this data as well, and then predicting itself. Is this a correct assumption, or am I misinterpreting how Tensorflow works?
The other issue is that when I try to use code that (based on other tutorials) which is supposed to output the probabilities of all of the 2165 possible outputs, I get the error:
InvalidArgumentError (see above for traceback): Shape [-1,2165] has negative dimensions
[[Node: y = Placeholder[dtype=DT_FLOAT, shape=[?,2165], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]
To me, it looks like it is the correct layer based on the 2165 value in the Tensor shape, but I don't understand the -1 value. So, to wrap up the summary, my questions are:
Based on the fact that I get the value that I have in the label of the input data, is this the correct method to make a classification using this model?
Am I missing a layer or have I configured the model incorrectly in order to extract the probabilities of all of the possible output classes, or am I using the wrong code to extract the information? I try to print out the accuracy to see if that would work, but instead it outputs the description of a tensor, so clearly that is incorrect as well.
(ADDITIONAL INFORMATION)
As requested, I'm also including the original code that was used to train the model, which is now below. You can see I do sort of a piece meal training of a limited number of related records at a time by their taxonomic relationships as I iterate through the file. This is mostly because the Mac that I'm training on (Mac Pro w/ 64GB ram) tends to give me the "Killed -9" error due to overuse of resources if I don't do it this way. There may be a better way to do it, but this seems to work.
Original Author: Aymeric Damien
Project: https://github.com/aymericdamien/TensorFlow-Examples/
from __future__ import print_function
import tensorflow as tf
import numpy as np
import csv
import random
# Parameters
num_epochs = 2
train_size = 1609
learning_rate = 0.001 #(larger >speed, lower >accuracy)
training_iters = 5000 # How much do you want to train (more = better trained)
batch_size = 32 #How many samples to train on, size of the training batch
display_step = 10 # How often to diplay what is going on during training
# Network Parameters
n_input = 10816 # MNIST data input (img shape: 28*28)...in my case 104x104 = 10816(rough array size)
n_classes = 2165 #3280 #2307 #787# Switched to 100 taxa/training set, dynamic was too wonky.
dropout = 0.75 # Dropout, probability to keep units. Jeffery Hinton's group developed it, that prevents overfitting to find new paths. More generalized model.
# Functions
def extract_data(filename):
print("extracting data...")
# arrays to hold the labels and feature vectors.
NUM_LABELS = 2165
NUM_FEATURES = 10826
taxCount = 0
taxCurrent = 0
labels = []
fvecs = []
rowCount = 0
#iterate over the rows, split the label from the features
#convert the labels to integers and features to floats
print("entering CNN loop")
for line in open(filename):
rowCount = rowCount + 1
row = line.split(',')
taxCurrent = row[3]
print("profile:", row[0:12])
labels.append(int(row[3]))
fvecs.append([float(x) for x in row [4:10820]])
#convert the array of float arrasy into a numpy float matrix
fvecs_np = np.matrix(fvecs).astype(np.float32)
#convert the array of int lables inta a numpy array
labels_np = np.array(labels).astype(dtype=np.uint8)
#convert the int numpy array into a one-hot matrix
labels_onehot = (np.arange(NUM_LABELS) == labels_np[:, None]).astype(np.float32)
print("arrays converted")
return fvecs_np, labels_onehot
# Create some wrappers for simplicity
def conv2d(x, W, b, strides=1): #Layer 1 : Convolutional layer
# Conv2D wrapper, with bias and relu activation
print("conv2d")
x = tf.nn.conv2d(x, W, strides=[1, strides, strides, 1], padding='SAME') # Strides are the tensors...list of integers. Tensors=data
x = tf.nn.bias_add(x, b) #bias is the tuning knob
return tf.nn.relu(x) #rectified linear unit (activation function)
def maxpool2d(x, k=2): #Layer 2 : Takes samples from the image. (This is a 4D tensor)
print("maxpool2d")
# MaxPool2D wrapper
return tf.nn.max_pool(x, ksize=[1, k, k, 1], strides=[1, k, k, 1],
padding='SAME')
# Create model
def conv_net(x, weights, biases, dropout):
print("conv_net setup")
# Reshape input picture
x = tf.reshape(x, shape=[-1, 104, 104, 1]) #-->52x52 , -->26x26x64
# Convolution Layer
conv1 = conv2d(x, weights['wc1'], biases['bc1']) #defined above already
# Max Pooling (down-sampling)
conv1 = maxpool2d(conv1, k=2)
print(conv1.get_shape)
# Convolution Layer
conv2 = conv2d(conv1, weights['wc2'], biases['bc2']) #wc2 and bc2 are just placeholders...could actually skip this layer...maybe
# Max Pooling (down-sampling)
conv2 = maxpool2d(conv2, k=2)
print(conv2.get_shape)
# Fully connected layer
# Reshape conv2 output to fit fully connected layer input
fc1 = tf.reshape(conv2, [-1, weights['wd1'].get_shape().as_list()[0]])
fc1 = tf.add(tf.matmul(fc1, weights['wd1']), biases['bd1'])
fc1 = tf.nn.relu(fc1) #activation function for the NN
# Apply Dropout
fc1 = tf.nn.dropout(fc1, dropout)
# Output, class prediction
out = tf.add(tf.matmul(fc1, weights['Wout']), biases['Bout'])
return out
def Train_Network(Txid_IN, Sess_File_Name):
import tensorflow as tf
tf.reset_default_graph()
x,y = 0,0
weights = {}
biases = {}
# tf Graph input
print("setting placeholders")
x = tf.placeholder(tf.float32, [None, n_input], name="x") #Gateway for data (images)
y = tf.placeholder(tf.float32, [None, n_classes], name="y") # Gateway for data (labels)
keep_prob = tf.placeholder(tf.float32) #dropout # Gateway for dropout(keep probability)
# Store layers weight & bias
#CREATE weights
weights = {
# 5x5 conv, 1 input, 32 outputs
'wc1': tf.Variable(tf.random_normal([5, 5, 1, 32]),name="wc1"), #
# 5x5 conv, 32 inputs, 64 outputs
'wc2': tf.Variable(tf.random_normal([5, 5, 32, 64]),name="wc2"),
# fully connected, 7*7*64 inputs, 1024 outputs
'wd1': tf.Variable(tf.random_normal([26*26*64, 1024]),name="wd1"),
# 1024 inputs, 10 outputs (class prediction)
'Wout': tf.Variable(tf.random_normal([1024, n_classes]),name="Wout")
}
biases = {
'bc1': tf.Variable(tf.random_normal([32]), name="bc1"),
'bc2': tf.Variable(tf.random_normal([64]), name="bc2"),
'bd1': tf.Variable(tf.random_normal([1024]), name="bd1"),
'Bout': tf.Variable(tf.random_normal([n_classes]), name="Bout")
}
# Construct model
print("constructing model")
pred = conv_net(x, weights, biases, keep_prob)
print(pred)
# Define loss(cost) and optimizer
#cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(pred, y)) Deprecated version of the statement
cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits = pred, labels=y)) #added reduce_mean 6/27
optimizer = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(cost)
# Evaluate model
correct_pred = tf.equal(tf.argmax(pred, 1), tf.argmax(y, 1))
accuracy = tf.reduce_mean(tf.cast(correct_pred, tf.float32))
print("%%%%%%%%%%%%%%%%%%%%")
print ("%% ", correct_pred)
print ("%% ", accuracy)
print("%%%%%%%%%%%%%%%%%%%%")
# Initializing the variables
#init = tf.initialize_all_variables()
init = tf.global_variables_initializer()
saver = tf.train.Saver()
fvecs_np, labels_onehot = extract_data("MicroarrayDataOUT.csv") #CHAGE TO PICORNAVIRUS!!!!!AHHHHHH!!!
print("starting session")
# Launch the graph
FitStep = 0
with tf.Session() as sess: #graph is encapsulated by its session
sess.run(init)
step = 1
# Keep training until reach max iterations (training_iters)
while step * batch_size < training_iters:
if FitStep >= 5:
break
else:
#iterate and train
print(step)
print(fvecs_np, labels_onehot)
for step in range(num_epochs * train_size // batch_size):
sess.run(optimizer, feed_dict={x: fvecs_np, y: labels_onehot, keep_prob:dropout}) #no dropout???...added Keep_prob:dropout
if FitStep >= 5:
break
#else:
###batch_x, batch_y = mnist.train.next_batch(batch_size)
# Run optimization op (backprop)
###sess.run(optimizer, feed_dict={x: batch_x, y: batch_y,
### keep_prob: dropout}) <<<<SOMETHING IS WRONG IN HERE?!!!
if step % display_step == 0:
# Calculate batch loss and accuracy
loss, acc = sess.run([cost, accuracy], feed_dict={x: fvecs_np,
y: labels_onehot,
keep_prob: 1.})
print("Iter " + str(step*batch_size) + ", Minibatch Loss= " + \
"{:.6f}".format(np.mean(loss)) + ", Training Accuracy= " + \
"{:.5f}".format(acc))
TrainAcc = float("{:.5f}".format(acc))
#print("******", TrainAcc)
if TrainAcc >= .99: #Changed from .95 temporarily
print(FitStep)
FitStep = FitStep+1
saver.save(sess, Sess_File_Name, global_step=1000) #
print("Saved Session:", Sess_File_Name)
step += 1
print("Optimization Finished!")
print("Testing Accuracy:", \
sess.run(accuracy, feed_dict={x: fvecs_np[:256],
y: labels_onehot[:256],
keep_prob: 1.}))
#feed_dictTEST = {x: fvecs_np[50]}
#prediction=tf.argmax(y,1)
#print(prediction)
#best = sess.run([prediction],feed_dictTEST)
#print(best)
print("DONE")
sess.close()
def Tax_Iterator(CSV_inFile, CSV_outFile): #Deprecate
#Need to copy *.csv file to MySQL for sorting
resultFileINIT = open(CSV_outFile,'w')
resultFileINIT.close()
TaxCount = 0
TaxThreshold = 2165
ThresholdStep = 2165
PrevTax = 0
linecounter = 0
#Open all GenBank profile list
for line in open(CSV_inFile):
linecounter = linecounter+1
print(linecounter)
resultFile = open(CSV_outFile,'a')
wr = csv.writer(resultFile, dialect='excel')
# Check for new TXID
row = line.split(',')
print(row[7], "===", PrevTax)
if row[7] != PrevTax:
print("X1")
TaxCount = TaxCount+1
PrevTax = row[7]
#Check it current Tax count is < or > threshold
# < threshold
print(TaxCount,"=+=", TaxThreshold)
if TaxCount<=3300:
print("X2")
CurrentTax= row[7]
CurrTxCount = CurrentTax
print("TaxCount=", TaxCount)
print( "Add to CSV")
print("row:", CurrentTax, "***", row[0:15])
wr.writerow(row[0:-1])
# is > threshold
else:
print("X3")
# but same TXID....
print(row[7], "=-=", CurrentTax)
if row[7]==CurrentTax:
print("X4")
CurrentTax= row[7]
print("TaxCount=", TaxCount)
print( "Add to CSV")
print("row:", CurrentTax, "***", row[0:15])
wr.writerow(row[0:-1])
# but different TXID...
else:
print(row[7], "=*=", CurrentTax)
if row[7]>CurrentTax:
print("X5")
TaxThreshold=TaxThreshold+ThresholdStep
resultFile.close()
Sess_File_Name = "CNN_VirusIDvSPECIES_XXALL"+ str(TaxThreshold-ThresholdStep)
print("<<<< Start Training >>>>"
print("Training on :: ", CurrTxCount, "Taxa", TaxCount, "data points.")
Train_Network(CurrTxCount, Sess_File_Name)
print("Training complete")
resultFileINIT = open(CSV_outFile,'w')
resultFileINIT.close()
CurrentTax= row[7]
#reset tax count
CurrTxCount = 0
TaxCount = 0
resultFile.close()
Sess_File_Name = "MicroarrayCNN_Data"+ str(TaxThreshold+ThresholdStep)
print("<<<< Start Training >>>>")
print("Training on :: ", CurrTxCount, "Taxa", TaxCount, "data points.")
Train_Network(CurrTxCount, Sess_File_Name)
resultFileINIT = open(CSV_outFile,'w')
resultFileINIT.close()
CurrentTax= row[7]
Tax_Iterator("MicroarrayInput.csv", "MicroarrayOutput.csv")
You defined prediction as prediction=tf.argmax(y,1). And in both feed_dict, you feed labels_onehot for y. Consequently, your "prediction" is always equal to the labels.
As you didn't post the code you used to train your network, I can't tell you what exactly you need to change.
Edit: I have isses understanding the underlying problem you're trying to solve - based on your code, you're trying to train a neural network with 2165 different classes using 1609 training examples. How is this even possible? If each example had a different class, there would still be some classes without any training example. Or does one image belong to many classes? From your statement at the beginning of your question, I had assumed you're trying to output a real-valued number between 0-1.
I'm actually surprised that the code actually worked as it looks like you're adding only a single number to your labels list, but your model expects a list with length 2165 for each training example.

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