title: How to normalize data consisting of few variables of zero value for all instances?
body: <p>I want to normalize data instances(1000 instances and 400 features) such that each feature has zero mean and unit variance. However, some features have zero value for all instances and  hence svm() command from R e1071 package gives error signal as &quot;In svm.default(x, y, scale = scale, ..., na.action = na.action) :  Variable(s) ‘X261’ and ‘X262’ and ‘X271’ and ‘X272’ and ‘X281’ and ‘X282’ and ‘X283’ constant. Cannot scale data. &quot;.
  How to solve this issue? Thanks.</p>