# unmkpp

Extract piecewise polynomial details

## Syntax

``````[breaks,coefs,L,order,dim] = unmkpp(pp)``````

## Description

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``````[breaks,coefs,L,order,dim] = unmkpp(pp)``` extracts information from the fields of the piecewise polynomial structure `pp`.```

## Examples

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Create a piecewise polynomial structure for the polynomial $f\left(x\right)={x}^{2}+x+1$ on the interval [0 3], and then extract the information from the fields of the structure.

`pp = mkpp([0 3],[1 1 1])`
```pp = struct with fields: form: 'pp' breaks: [0 3] coefs: [1 1 1] pieces: 1 order: 3 dim: 1 ```
`[breaks,coefs,L,order,dim] = unmkpp(pp)`
```breaks = 1×2 0 3 ```
```coefs = 1×3 1 1 1 ```
```L = 1 ```
```order = 3 ```
```dim = 1 ```

## Input Arguments

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Piecewise polynomial, specified as a structure. You can create `pp` using `spline`, `pchip`, `interp1`, or the spline utility function `mkpp`.

## Output Arguments

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Break points, returned as a vector of length `L+1` with strictly increasing elements that represent the start and end of each of `L` intervals.

Polynomial coefficients, returned as an `L`-by-`k` matrix with each row `coefs(i,:)` containing the local coefficients of an order `k` polynomial on the ith interval, `[breaks(i),breaks(i+1)]`.

Number of intervals, returned as a scalar.

Order of polynomials, returned as a scalar.

Dimension of target, returned as a scalar or vector.