Hi I maybe mistaken but
scale(your.matrix) gives you matrix scaled in the way you want. > apply(scale(as.matrix(kalcin[,3:7])), na.rm=T,2,sd) vodofe stroz l a b 1 1 1 1 1 > apply(scale(as.matrix(kalcin[,3:7])), na.rm=T,2,mean) vodofe stroz l a b 1.990322e-15 -5.025086e-14 8.581765e-14 3.588313e-15 -1.370877e-15 HTH Petr On 20 Sep 2005 at 9:13, Frank Schmid wrote: > I have a data matrix containing around 180 variables and more than 470 > observations for each and no missing values. > > Within a for-loop, the first step of calculations is to standardize > each column, such that the mean of each column is zero and the sd is > one. The for-loop starts with a subset of the initial matrix and > includes all columns but only a third of the rows. The loop "works > itself through" the whole matrix and adds everytimes one row, so in > the last loop, the whole data matrix is used. The standardization > within the loop is done using the "scale" function. > > Now, my problem is that with all the 180 variables, either the > for-loop or the scale function does not work properly, as the > resulting matrix after the standardization does not have the same > dimensions anymore as it had before. The matrix is no longer a 180*470 > matrix, but a 180*130 matrix. If, however, I include only 130 > variables instead of 180, the result is correct, the dimensions are > right and each column indeed has mean zero and sd one. > > Can anyone please tell me, why this problem appears? Would there be a > way that gives the same result without using a for-loop? > > Thanks > > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html Petr Pikal [EMAIL PROTECTED] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html