# QR decomposition (for TI compatibility): QR

### 5.49.3 QR decomposition (for TI compatibility): QR

The QR command finds the QR decomposition of a matrix.

- QR takes three arguments:
  - A, a square matrix.
  - q and r, two variable names.
- QR(A,q,r) returns the matrix R from the QR decomposition of A, and assigns the matrices Q and R to the variables q and r.

#### Example.

Input:

QR([[3,5],[4,5]],Q,R)

Output (the matrix R):

⎡
⎢
⎣

5 | 7
0 | 1

⎤
⎥
⎦

Input:

Q

Output (the matrix Q):

⎛
⎜
⎜
⎜
⎜
⎜
⎜
⎜
⎝

3
5

4
5

4
5

−

3
5

⎞
⎟
⎟
⎟
⎟
⎟
⎟
⎟
⎠