Itseez/opencv — pull request #1004 by jet47 (2013-06-14 08:56:40+00:00)
Title: Fix for bug #3068 (PCA::computeVar for double input)

http://code.opencv.org/issues/3068

The matrix `g` can have `CV_32F` or `CV_64F` type, but `g.at` uses only `float` template.
The fix adds specialization for `double` type.