[R] SVM module: scaling data applied to new test set without using SVMagain

[David Meyer]

seidel at micro-biolytics.com wrote:
> 
> Hello!
> 
> We are new in  using R.  We use the SVM module from the library 'e1071'
> for training.
> 
> Problem formulation:
> 
> a classification has been performed using SVM module (linear kernel).
> Later, a new data set (test set) comparable to the training data shall be
> scaled in the same way  as the training set (using the same scaling
> parameter set, but without using the SVM again to save time). We found the
> scaling matrices, but we do not know, how to apply them.

[note: in the `x.scale' element of the fitted model]

> 
> How must the scaling parameter matrices (scaled:center and scaled:scale)
> be applied to the test data set to receive the same scaling as it would
> have been done by the SVM module?

the function `scale' has two parameters: `center' and `scale'.
So, you could do sth. like:

scale(newdata, 
      center = model$x.scale$"scaled:center", 
      scale = model$x.scale$"scaled:scale")

best,
	
David

> 
> Thanx very much in advance!
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> 
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