lapack/gonum: clean up parameter checks in Dgelqf
@@ -21,33 +21,45 @@ import (
//
// tau must have length at least min(m,n), and this function will panic otherwise.
func (impl Implementation) Dgelqf(m, n int, a []float64, lda int, tau, work []float64, lwork int) {
+ switch {
+ case m < 0:
+ panic(mLT0)
+ case n < 0:
+ panic(nLT0)
+ case lda < max(1, n):
+ panic(badLdA)
+ case lwork < max(1, m) && lwork != -1:
+ panic(badWork)
+ case len(work) < max(1, lwork):
+ panic(shortWork)
+ }
+
+ k := min(m, n)
+ if k == 0 {
+ work[0] = 1
+ return
+ }
+
nb := impl.Ilaenv(1, "DGELQF", " ", m, n, -1, -1)
- lworkopt := m * max(nb, 1)
if lwork == -1 {
- work[0] = float64(lworkopt)
+ work[0] = float64(m * nb)
return
}
- checkMatrix(m, n, a, lda)
- if len(work) < lwork {
- panic(shortWork)
- }
- if lwork < m {
- panic(badWork)
+
+ if len(a) < (m-1)*lda+n {
+ panic("lapack: insufficient length of a")
}
- k := min(m, n)
if len(tau) < k {
panic(badTau)
}
- if k == 0 {
- return
- }
+
// Find the optimal blocking size based on the size of available memory
// and optimal machine parameters.
nbmin := 2
var nx int
iws := m
ldwork := nb
- if nb > 1 && k > nb {
+ if 1 < nb && nb < k {
nx = max(0, impl.Ilaenv(3, "DGELQF", " ", m, n, -1, -1))
if nx < k {
iws = m * nb
@@ -59,7 +71,7 @@ func (impl Implementation) Dgelqf(m, n int, a []float64, lda int, tau, work []fl
}
// Computed blocked LQ factorization.
var i int
- if nb >= nbmin && nb < k && nx < k {
+ if nbmin <= nb && nb < k && nx < k {
for i = 0; i < k-nx; i += nb {
ib := min(k-i, nb)
impl.Dgelq2(ib, n-i, a[i*lda+i:], lda, tau[i:], work)
@@ -81,4 +93,5 @@ func (impl Implementation) Dgelqf(m, n int, a []float64, lda int, tau, work []fl
if i < k {
impl.Dgelq2(m-i, n-i, a[i*lda+i:], lda, tau[i:], work)
}
+ work[0] = float64(iws)
}
