Removed a single usage of Instances.attributeStats() for speed reasons.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11294 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Removed a single usage of Instances.attributeStats() for speed reasons.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11295 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Replaced computation of standard deviation via calls to attributeStats() with calls to Instances.variance().

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11296 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Replaced computation of standard deviation via calls to attributeStats() with calls to Instances.variance().

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11297 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Added method to compute multiple variances simultaneously in Instances. This method is now used in SimpleKMeans. Rearranged loops, removed testing for missing values, and made some other small modifications in EM. EM now also has a parameter that allows the user to specify the number of k-means runs to perform for initialization.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11298 e0a1b77d-ad91-4216-81b1-defd5f83fa92
From Eibe: Added method to compute multiple variances simultaneously in Instances. This method is now used in SimpleKMeans. Rearranged loops, removed testing for missing values, and made some other small modifications in EM. EM now also has a parameter that allows the user to specify the number of k-means runs to perform for initialization.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@11299 e0a1b77d-ad91-4216-81b1-defd5f83fa92