ValueError: Error when checking target: expected activation_98 to have 3 dimensions, but got array with shape (4, 224, 224, 2)

[samuelTyh]

Something wrong in the cell below
model.fit_generator(gen_mix, steps_per_epoch=5, epochs=1, verbose=0, callbacks=[tqdm], class_weight=sample_weights)

[hearsh]

Hey even I am having the same problem

[patallenDataSci]

After running:
X, y = next(gen_mix)

y.shape returns:
(4, 224, 224, 2) for me rather than:
(4, 50176, 2) in the original notebook

I am not quite sure what to change in seg_gen_mix or segm_generator to flatten the array into the vector format expected

[hxtkyne]

change like below:

def get_item(self, idx):
    slice_r = self.get_slice(self.ri[idx], self.ro)
    slice_c = self.get_slice(self.ci[idx], self.co)
    x = self.x[idx][slice_r, slice_c]
    y = self.y[idx][slice_r, slice_c]
    y = np.reshape(y, [self.ro * self.co, -1]) # add this
    if self.train and (random.random()>0.5): 
        y = y[:,::-1]
        x = x[:,::-1]
    if not self.waldo and np.sum(y)!=0:
        return None
    return x, to_categorical(y, num_classes=2)