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**Owning Class: **linalgebra

**Requires: **MathScript RT Module

r = qr(a)

r = qr(a, 0)

[q, r] = qr(a)

[q, r] = qr(a, 0)

[q, r, pm] = qr(a)

[q, r, pv] = qr(a, 0)

Performs the QR decomposition of an input matrix with or without column pivoting.

Name | Description |
---|---|

a |
Specifies a matrix. |

0 |
Specifies that LabVIEW computes the economy size QR decomposition such that the size of q is m-by-min(m, n) and the size of r is min(m, n)-by-n, where a is an m-by-n matrix. |

Name | Description |
---|---|

q |
Returns the orthogonal or unitary matrix of the QR decomposition of a. |

r |
Returns the upper triangular matrix of the QR decomposition of a. |

pm |
Returns the pivot matrix of the QR decomposition of a. pm is a matrix of 32-bit signed integers. |

pv |
Returns the pivot vector of the QR decomposition of a. pv is a row vector of 32-bit signed integers. |

The QR decomposition of a matrix **a** without column pivoting computes matrices **q** and **r** such that **q*****r** = **a**, where **q** is an orthogonal or unitary matrix and **r** is an upper triangular matrix.

The QR decomposition of a matrix **a** with column pivoting computes matrices **q** and **r** and the pivot matrix **pm** or the pivot vector **pv** such that **q*****r** = **a*****pm** or **q*****r** = **a**(**pv**). LabVIEW performs column pivoting on **a** such that the diagonal elements of **r** are in decreasing order.

The following table lists the support characteristics of this function.

Supported in the LabVIEW Run-Time Engine | Yes |

Supported on RT targets | Yes |

Suitable for bounded execution times on RT | Not characterized |

A = rand(2)

[Q, R, P] = qr(A)

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