# Transform the Scaled Matrix to its Original Form in R Programming – Using Matrix Computations

• Last Updated : 18 Jan, 2022

In R programming, a matrix can be scaled and centered using `scale()` function. But, there is no in-built function to transform the scaled matrix back to the original matrix. In this article, we’ll learn to transform the scaled matrix back to the original matrix using some simple computations.

#### Using Matrix Attributes

Attributes of the scaled matrix can be used to unscale the matrix back to its original matrix.

## R

 `# Create matrix``mt <- ``matrix``(``c``(1:20), ncol = 5)`` ` `# Print original matrix``cat``(``"Original matrix:\n"``)``print``(mt)`` ` `# Scale the matrix``scaled.mt <- ``scale``(mt)`` ` `# Print Scaled matrix``cat``(``"Scaled matrix:\n"``)``print``(scaled.mt)`` ` `# Unscale the matrix``unscaled.mt <- ``t``(``apply``(scaled.mt, 1, ``                ``function``(r) r * ``attr``(scaled.mt, ``'scaled:scale'``) + ``                                ``attr``(scaled.mt, ``'scaled:center'``)))`` ` `# Print Unscaled matrix``cat``(``"Unscaled matrix:\n"``)``print``(unscaled.mt)`

Output:

```Original matrix:
[, 1] [, 2] [, 3] [, 4] [, 5]
[1, ]    1    5    9   13   17
[2, ]    2    6   10   14   18
[3, ]    3    7   11   15   19
[4, ]    4    8   12   16   20
Scaled matrix:
[, 1]       [, 2]       [, 3]       [, 4]       [, 5]
[1, ] -1.1618950 -1.1618950 -1.1618950 -1.1618950 -1.1618950
[2, ] -0.3872983 -0.3872983 -0.3872983 -0.3872983 -0.3872983
[3, ]  0.3872983  0.3872983  0.3872983  0.3872983  0.3872983
[4, ]  1.1618950  1.1618950  1.1618950  1.1618950  1.1618950
attr(, "scaled:center")
[1]  2.5  6.5 10.5 14.5 18.5
attr(, "scaled:scale")
[1] 1.290994 1.290994 1.290994 1.290994 1.290994
Unscaled matrix:
[, 1] [, 2] [, 3] [, 4] [, 5]
[1, ]    1    5    9   13   17
[2, ]    2    6   10   14   18
[3, ]    3    7   11   15   19
[4, ]    4    8   12   16   20
```

#### Using Mean and Standard Deviation

In this example, we’ll unscale the scaled matrix using mean and standard deviation of the original matrix.

## R

 `# Create matrix``a <- ``rnorm``(5, 5, 2)``b <- ``rnorm``(5, 7, 5) `` ` `mt <- ``cbind``(a, b)`` ` `# get center and scaling values ``m <- ``apply``(df, 2, mean)``s <- ``apply``(df, 2, sd)`` ` `# Print original matrix``cat``(``"Original matrix:\n"``)``print``(mt)`` ` `# Scale the matrix``scaled.mt <- ``scale``(mt, center = m, scale = s)`` ` `# Print Scaled matrix``cat``(``"Scaled matrix:\n"``)``print``(scaled.mt)`` ` `# Unscale the matrix``unscaled.mt <- ``t``((``t``(scaled.mt) * s) + m)`` ` `# Print Unscaled matrix``cat``(``"Unscaled matrix:\n"``)``print``(unscaled.mt)`

#### Output:

```Original matrix:
a          b
[1, ] 5.552301  1.9865159
[2, ] 3.936486 17.5327829
[3, ] 5.379720 15.0981877
[4, ] 3.546333  0.5230305
[5, ] 5.043194  2.0930855

Scaled matrix:
a         b
[1, ]  0.01543556 -2.062174
[2, ] -0.69057233  5.252016
[3, ] -0.05997146  4.106591
[4, ] -0.86104456 -2.750713
[5, ] -0.20701146 -2.012036
attr(, "scaled:center")
a        b
5.516974 6.369655
attr(, "scaled:scale")
a        b
2.288663 2.125494

Unscaled matrix:
a          b
[1, ] 5.552301  1.9865159
[2, ] 3.936486 17.5327829
[3, ] 5.379720 15.0981877
[4, ] 3.546333  0.5230305
[5, ] 5.043194  2.0930855
attr(, "scaled:center")
a        b
5.516974 6.369655
attr(, "scaled:scale")
a        b
2.288663 2.125494
```

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