mat: generalise SolveVec vector parameters

mat/solve.go

@@ -104,24 +104,37 @@ func (m *Dense) Solve(a, b Matrix) error {
 }
 
 // SolveVec finds a minimum-norm solution to a system of linear equations defined
-// by the matrix a and the right-hand side vector b. If A is singular or
+// by the matrix a and the right-hand side column vector b. If A is singular or
 // near-singular, a Condition error is returned. Please see the documentation for
 // Dense.Solve for more information.
-func (v *VecDense) SolveVec(a Matrix, b *VecDense) error {
-	if v != b {
-		v.checkOverlap(b.mat)
+func (v *VecDense) SolveVec(a Matrix, b Vector) error {
+	if _, bc := b.Dims(); bc != 1 {
+		panic(ErrShape)
 	}
 	_, c := a.Dims()
+
 	// The Solve implementation is non-trivial, so rather than duplicate the code,
 	// instead recast the VecDenses as Dense and call the matrix code.
+
+	if rv, ok := b.(RawVectorer); ok {
+		bmat := rv.RawVector()
+		if v != b {
+			v.checkOverlap(bmat)
+		}
+		v.reuseAs(c)
+		m := v.asDense()
+		// We conditionally create bm as m when b and v are identical
+		// to prevent the overlap detection code from identifying m
+		// and bm as overlapping but not identical.
+		bm := m
+		if v != b {
+			b := VecDense{mat: bmat, n: b.Len()}
+			bm = b.asDense()
+		}
+		return m.Solve(a, bm)
+	}
+
 	v.reuseAs(c)
 	m := v.asDense()
-	// We conditionally create bm as m when b and v are identical
-	// to prevent the overlap detection code from identifying m
-	// and bm as overlapping but not identical.
-	bm := m
-	if v != b {
-		bm = b.asDense()
-	}
-	return m.Solve(a, bm)
+	return m.Solve(a, b)
 }