training accuracy always be zero, why?

[white2018]

Thanks for your contribution.

I have downloaded the code and run it ok for 8 letters recognition. However, Something happened when I recode your code to recognize 14 or more letters. The problem is that training accuracy always be zero, even after dozen epoches' training, each epoch has 1w pictures.

2017-08-07 18:16:11,402 - root - INFO - Epoch[11] Batch [100] Speed: 271.67 samples/sec accuracy=0.000000
2017-08-07 18:16:15,152 - root - INFO - Epoch[11] Batch [200] Speed: 266.71 samples/sec accuracy=0.000000
2017-08-07 18:16:18,915 - root - INFO - Epoch[11] Batch [300] Speed: 265.76 samples/sec accuracy=0.000000
2017-08-07 18:16:22,544 - root - INFO - Epoch[11] Batch [400] Speed: 275.58 samples/sec accuracy=0.000000
2017-08-07 18:16:26,258 - root - INFO - Epoch[11] Batch [500] Speed: 269.32 samples/sec accuracy=0.000000
2017-08-07 18:16:30,039 - root - INFO - Epoch[11] Batch [600] Speed: 264.47 samples/sec accuracy=0.000000
2017-08-07 18:16:33,699 - root - INFO - Epoch[11] Batch [700] Speed: 273.27 samples/sec accuracy=0.000000
2017-08-07 18:16:37,393 - root - INFO - Epoch[11] Batch [800] Speed: 270.71 samples/sec accuracy=0.000000
2017-08-07 18:16:41,054 - root - INFO - Epoch[11] Batch [900] Speed: 273.20 samples/sec accuracy=0.000000

[szad670401]

please check your the license plate images which script generated are right?

[white2018]

It looks like it happens for the training images, in which the stroke width varies. Does it mean this algorithm only works fine for the fixed stroke width?