Function qrX

qrX(q: QR, options?: { complete?: boolean; ncol?: number }): number[][]
Reconstructs the original matrix from a QR decomposition, with columns back in their original order. Equivalent to R's qr.X().

If the decomposition was pivoted, ncol smaller than the number of columns is an error (as in R).
Parameters
- q: QR
  A QR decomposition from qr.
- options: { complete?: boolean; ncol?: number } = {}
  complete: whether the default ncol is the number of rows (true) or min(nrow, ncol) (false, the default). ncol: the number of columns to return, from 0 to max(nrow, ncol); columns beyond the original ones are taken from Q (as in R). A larger ncol is an error (R pads zero columns).
Returns number[][]
The reconstructed matrix as an array of rows.
Example
```
qrX(qr([[3, 0], [4, 5]])); // [[3, 0], [4, 5]]
```
- Defined in linalg/qr.ts:741