rolling_corr not in [-1,1] when using 'center' flag

[iamlemec]

The function rolling_corr returns values with absolute value greater than one when using the 'center' flag. The following code will reproduce (with high probability):

df = pandas.DataFrame(numpy.random.rand(30,2))
pandas.rolling_corr(df[0],df[1],5,center=True)

It seems like passing center to rolling_count and rolling_mean in rolling_corr would be in order?

Also, unrelated to this, calling rolling_corr(5,6,10) will hit the recursion limit because _flex_binary_moment keeps switching the first two arguments around.

[ghost]

Thanks, we'll handle that along with #2953.

[ghost]

#2953 tests for corr>1, and includes a fix.

[ghost]

recursion error fixed in master via b6b6023
rolling_curr>1 issue via cd07f4b