Gscaler
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Purpose
GSCALER Applies group/block scaling to submatrices of a single matrix.
Synopsis
- gys = gscaler(xin,numblocks,mxs,stdxs)
- xin = gscaler(gys,numblocks,mxs,stdxs,undo)
Description
Inputs are a matrix (xin) (class "double"), the number of sub-matrices/ blocks (numblocks), an offset vector (mxs), and a scale vector (stdxs).
See GSCALE for descriptions of (mxs) and (stdxs).
Note that size(xin,2)/numblocks must be a whole number.
When numblocks = 1, all variables are scaled as a single block.
When numblocks = 0, each variable is handled on its own and gscaler is equivalent to the SCALE function.
If the optional input (undo) is included with a value of 1 (one), then the input is assumed to be (gys) and is unscaled and uncentered to give the original (xin) matrix.
In a standard call, the output is the scaled matrix (gys). When undo is provided, the output is the unscaled original matrix (xin).
Examples
Scale a matrix a that has two blocks augmented together using GSCALE:
>> a = [[1 2 3; 4 5 6; 7 8 9] [11 12 13; 14 15 16; 17 18 19]];
>> [gxs,mxs,stdxs] = gscale(a,2);
>> gxs
gxs =
-0.5774 -0.5774 -0.5774 -0.5774 -0.5774 -0.5774
0 0 0 0 0 0
0.5774 0.5774 0.5774 0.5774 0.5774 0.5774
>> mxs
mxs =
4 5 6 14 15 16
>> stdxs
stdxs =
3 3 3 3 3 3
Now scale a new matrix b that has two blocks augmented together:
>> b = [[2 3 4; 4 5 6; 6 7 8] [10 11 12; 14 15 16; 18 19 20]]
b =
2 3 4 10 11 12
4 5 6 14 15 16
6 7 8 18 19 20
>> gys = gscaler(b,2,mxs,stdxs)
gys =
-0.3849 -0.3849 -0.3849 -0.7698 -0.7698 -0.7698
0 0 0 0 0 0
0.3849 0.3849 0.3849 0.7698 0.7698 0.7698