我正在使用树莓及其本地操作系统，进行一些面部识别测试， 我有一个问题，是下一个：
OpenCV Error: Bad argument (At least two classes are needed to perform a LDA. Reason: Only one class was given!) in lda, file /build/opencv-U1UwfN/opencv-2.4.9.1+dfsg1/modules/contrib/src/lda.cpp, line 1010
Traceback (most recent call last):
File "reconocimiento.py", line 20, in <module>
model.train(images,lables)
cv2.error: /build/opencv-U1UwfN/opencv-2.4.9.1+dfsg1/modules/contrib/src/lda.cpp:1010: error: (-5) At least two classes are needed to perform a LDA. Reason: Only one class was given! in function lda
感谢您的帮助，希望我能找到答案：（