mapstd
Process matrices by mapping each row’s means to 0 and deviations to 1
Syntax
[Y,PS] = mapstd(X,ymean,ystd)
[Y,PS] = mapstd(X,FP)
Y = mapstd('apply',X,PS)
X = mapstd('reverse',Y,PS)
dx_dy = mapstd('dx_dy',X,Y,PS)
Description
mapstd
processes matrices by transforming the mean and standard
deviation of each row to ymean
and ystd
.
[Y,PS] = mapstd(X,ymean,ystd)
takes X
and optional
parameters,
X 

ymean  Mean value for each row of 
ystd  Standard deviation for each row of 
and returns
Y 

PS  Process settings that allow consistent processing of values 
[Y,PS] = mapstd(X,FP)
takes parameters as a struct:
FP.ymean
, FP.ystd
.
Y = mapstd('apply',X,PS)
returns Y
, given
X
and settings PS
.
X = mapstd('reverse',Y,PS)
returns X
, given
Y
and settings PS
.
dx_dy = mapstd('dx_dy',X,Y,PS)
returns the reverse derivative.
Examples
Here you format a matrix so that the minimum and maximum values of each row are mapped to default mean and STD of 0 and 1.
x1 = [1 2 4; 1 1 1; 3 2 2; 0 0 0] [y1,PS] = mapstd(x1)
Next, apply the same processing settings to new values.
x2 = [5 2 3; 1 1 1; 6 7 3; 0 0 0] y2 = mapstd('apply',x2,PS)
Reverse the processing of y1
to get x1
again.
x1_again = mapstd('reverse',y1,PS)
More About
Algorithms
The function assumes that X
only contains finite real values.
Additionally, the result for each row depends on the elements in that row.
If the elements of the row are not all equal, then the function transforms the mean and standard deviation of each row to
ymean
(default0
) andystd
(default1
).y = (xxmean)*(ystd/xstd) + ymean;
If the elements of the row are all equal, then the function does not modify the data in that row (
y=x
).
Version History
Introduced in R2006a