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# removerows

Process matrices by removing rows with specified indices

## Syntax

[Y,PS] = removerows(X,'ind',ind)
[Y,PS] = removerows(X,FP)
Y = removerows('apply',X,PS)
X = removerows('reverse',Y,PS)
dx_dy = removerows('dx',X,Y,PS)
dx_dy = removerows('dx',X,[],PS)
name = removerows('name')
fp = removerows('pdefaults')
names = removerows('pdesc')
removerows('pcheck',FP)

## Description

removerows processes matrices by removing rows with the specified indices.

[Y,PS] = removerows(X,'ind',ind) takes X and an optional parameter,

 X N-by-Q matrix or a 1-by-TS row cell array of N-by-Q matrices ind Vector of row indices to remove (default is [])

and returns

 Y Each M-by-Q matrix, where M == N-length(ind) (optional) PS Process settings that allow consistent processing of values

[Y,PS] = removerows(X,FP) takes parameters as a struct: FP.ind.

Y = removerows('apply',X,PS) returns Y, given X and settings PS.

X = removerows('reverse',Y,PS) returns X, given Y and settings PS.

dx_dy = removerows('dx',X,Y,PS) returns the M-by-N-by-Q derivative of Y with respect to X.

dx_dy = removerows('dx',X,[],PS) returns the derivative, less efficiently.

name = removerows('name') returns the name of this process method.

fp = removerows('pdefaults') returns the default process parameter structure.

names = removerows('pdesc') returns the process parameter descriptions.

removerows('pcheck',FP) throws an error if any parameter is illegal.

## Examples

Here is how to format a matrix so that rows 2 and 4 are removed:

```x1 = [1 2 4; 1 1 1; 3 2 2; 0 0 0]
[y1,ps] = removerows(x1,'ind',[2 4])
```

Next, apply the same processing settings to new values.

```x2 = [5 2 3; 1 1 1; 6 7 3; 0 0 0]
y2 = removerows('apply',x2,ps)
```

Reverse the processing of y1 to get x1 again.

```x1_again = removerows('reverse',y1,ps)
```

expand all

### Algorithms

In the reverse calculation, the unknown values of replaced rows are represented with NaN values.