# qrsol¶

## Purpose¶

Computes the solution of $$Rx = b$$ where $$R$$ is an upper triangular matrix.

## Format¶

x = qrsol(b, R)
Parameters
• b (PxL matrix) – data

• R (PxP matrix) – upper triangular matrix

Returns

x (PxL matrix) – solution of $$Rx = b$$ where $$R$$ is an upper triangular matrix.

## Remarks¶

qrsol() applies a backsolve to $$Rx = b$$ to solve for x. Generally R will be the R matrix from a QR factorization. qrsol() may be used, however, in any situation where R is upper triangular.

qrsol.src