{\boldsymbol {y}}\leftarrow \alpha {\boldsymbol {x}}+{\boldsymbol {y}}} (called "axpy", "a x plus y") and several other operations. This level contains matrix-vector...

arrays or sections of arrays; e.g., an axpy-style function that is ordinarily written // y ← α x + y void axpy(int n, float alpha, const float *x, float...

matrix-vector multiplication, but rather only one vector dot product, and then one axpy operation. This means its arithmetic complexity is of the same order of two...

recursion. There are more efficient and preconditioned variants with fewer AXPYs. Compare with the article. First you choose x 0 ∈ R n {\displaystyle x_{0}\in...