How to generate coded variables ( ±1 ) from a predictor matrix for a linear model in Response Surface design

The variables are T,V,C & A T=[15,5,15,5, 15,5,15,5, 15,5,15,5, 15,5,15,5]'; V=[10,5,5,10,5,10,10,5,5,10,10,5,10,5,5,10]'; C=[98,98,92,92,98,98,92,92,98,98,92,92,98,98,92,92]'; A=[25,25,25,25,15,15,15,15, 25,25,25,25,15,15,15,15]'; X=[T V C A]

It is required to generate the coded variables in ±1 for each of the factors in the design matrix,X.The coded variables will be used for regression analysis.I am using Matlab 2007b

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I suggest you consider Dummy Indicator Variables. (They are in the 2012b documentation. I do not know if they would apply to 2007b.)