Question

我在fit_generator中遇到了一个奇怪的问题

model.fit_generator(generate_arrays_from_file(trainSizeListImgDic[s], s, batchSize), steps_per_epoch=math.floor(size / batchSize), epochs=20,
                            verbose=2, validation_data=generate_arrays_from_file(testSizeListImgDic[s], s, batchSize),
                            validation_steps=vs,callbacks=[EarlyStoppingByAccVal(monitor='val_acc', value=0.90, verbose=1),checkpointer])

和我的generate_arrays_from_file读取：

def generate_arrays_from_file( SizeListImg ,img_size,batch):
size = len(SizeListImg.images)
dim = re.split('[,()]', img_size)
dataX = np.zeros((batch, int(dim[1]), int(dim[2]), 1), dtype=np.float32)
dataY = np.zeros((batch, num_classes), dtype=np.float32)
loopcount  =  math.floor( size/batch )-1
if loopcount==0:
    loopcount = 1
counter = 0
while (True):
    i = random.randint(0,loopcount)
    for ind in range( (i*batch) , (i + 1)*batch ):
        try:
            dataX[counter, :, :, 0] = SizeListImg.images[ind]
        except :  
            print('dim='+ str(dim) )
            print('error counter=' + str(counter) + "  i="+str(i) + "  ind=" + str(ind) + "  batch="+str(batch) + "\n" )
            print("SizeListImg.images="+str( len(SizeListImg.images) ) )
            print( "img0 = "+SizeListImg.images_names[0])
            print("img1 = " + SizeListImg.images_names[1])
            print("img2 = " + SizeListImg.images_names[2])
            print("img3 = " + SizeListImg.images_names[3])

        for j, imgClass in enumerate(imgClasses):
            dataY[counter, j] = (SizeListImg.labels[ind] == imgClass)
        counter += 1
        if counter>=batch:
            yield (dataX,dataY)
            counter = 0
            dataX = np.zeros((batch, int(dim[1]), int(dim[2]), 1), dtype=np.float32)    #not tf.zeros((25, 200, 200, 1))  please noted different:  np.zeros(
            dataY = np.zeros((batch, num_classes), dtype=np.float32)

在训练过程中，我发现训练图像139的大小减小为验证图像22的大小，这导致索引错误，但是图像确实来自训练图像集。但是，如果我将批次从20减少到10，则没有任何错误。 fit_generator对我有任何阴谋吗？

在fit_generator中，training_generator受validation_generator影响

0 个答案: