# unmkpp

Extract piecewise polynomial details

## Description

example

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

## Examples

collapse all

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

collapse all

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

## Output Arguments

collapse all

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.

## Version History

Introduced before R2006a