### Navigation

- index
- modules |
- modules |
- next |
- previous |
- SciPy v0.9 Reference Guide (DRAFT) »
- Maximum entropy models (`scipy.maxentropy`) »

# scipy.maxentropy.maxentutils.columnvariances

`scipy.maxentropy.maxentutils.``columnvariances`(A)

  This is a wrapper for general dense or sparse dot products.

  It is not necessary except as a common interface for supporting ndarray, scipy spmatrix, and PySparse arrays.

  Returns a dense (1 x n) vector with unbiased estimators for the column variances for each column of the (m x n) sparse or dense matrix A. (The normalization is by (m - 1).)

      >>> a = numpy.array([[1,2], [3,4]], 'd')
      >>> columnvariances(a)
      array([ 2.,  2.])

### Navigation

- index
- modules |
- modules |
- next |
- previous |
- SciPy v0.9 Reference Guide (DRAFT) »
- Maximum entropy models (`scipy.maxentropy`) »