Documentation for GradientVectorSobel and GradientVectorPrewitt

Hi,
there is documented GradientVectorSobel function for example on https://software.intel.com/en-us/node/504474 and there is mentioned Gx kernel.
I am not sure if it is correct documented, IMO it should be :
+1  0  -1
+2  0  -2
+1  0  -1
It seems to me that this kernel is used in reality by GradientVectorSobel as stated also for example on https://en.wikipedia.org/wiki/Sobel_operator