nanmean - np - np.mean - errror

[venkim_python]

I have fairly simple code to calculate mean. Basically I am reading mnist data, find the PCA and finding the mean of PCA1 and PCA2. The first few columns of PCA1, PCA2 are shown below. I am trying to find the mean of that data. I am confused how the mean could be something like e -power- negative 14.  Something is going wrong. I tried plain np.mean with axis=0, then nanmean - still the mean looks way off. If I chop off the last row it seemed to work at times. That is not consistent. The mean seems to be way out of range. The minimum is something like -1550 and max is like 1400 and for column 2 - 1300 to +2200. The mean could not be that small like e to power -14. 

Please help.

def findMean(X):
    X = X.astype('float64')
    badMU=np.nanmean(X,axis=0);
    print("from inside findMean print two rows of mean" )
    print(badMU[0:2])

    return badMU

Here is the output - excerpt only.

Output:
Print columns 1 and 2 of 5 rows of P i.e., P[:5,0:2]
[[ -177.01262488 -1123.38369215]
 [ -486.95502974   953.72782595]
 [ -701.57667656   722.54538116]
 [ -739.68606132   625.34125527]
 [  496.35283147  -371.99788225]]
Recovering X
Test overall mean of P - just print a few cols
from inside findMean print two rows of mean
[ -3.54114684e-14  -1.08559058e-14]

get min and max for col0 and col1 from P
Num entries in P is = 12593