@@ -794,6 +794,54 @@ func (impl Implementation) Dlaswp(n int, a []float64, lda, k1, k2 int, ipiv []in
794794 lapacke .Dlaswp (n , a , lda , k1 + 1 , k2 + 1 , ipiv32 , incX )
795795}
796796
797+ // Dpbcon returns an estimate of the reciprocal of the condition number (in the
798+ // 1-norm) of an n×n symmetric positive definite band matrix using the Cholesky
799+ // factorization
800+ // A = Uᵀ*U if uplo == blas.Upper
801+ // A = L*Lᵀ if uplo == blas.Lower
802+ // computed by Dpbtrf. The estimate is obtained for norm(inv(A)), and the
803+ // reciprocal of the condition number is computed as
804+ // rcond = 1 / (anorm * norm(inv(A))).
805+ //
806+ // The length of work must be at least 3*n and the length of iwork must be at
807+ // least n.
808+ func (impl Implementation ) Dpbcon (uplo blas.Uplo , n , kd int , ab []float64 , ldab int , anorm float64 , work []float64 , iwork []int ) (rcond float64 ) {
809+ switch {
810+ case uplo != blas .Upper && uplo != blas .Lower :
811+ panic (badUplo )
812+ case n < 0 :
813+ panic (nLT0 )
814+ case kd < 0 :
815+ panic (kdLT0 )
816+ case ldab < kd + 1 :
817+ panic (badLdA )
818+ case anorm < 0 :
819+ panic (badNorm )
820+ }
821+
822+ // Quick return if possible.
823+ if n == 0 {
824+ return 1
825+ }
826+
827+ switch {
828+ case len (ab ) < (n - 1 )* ldab + kd + 1 :
829+ panic (shortAB )
830+ case len (work ) < 3 * n :
831+ panic (shortWork )
832+ case len (iwork ) < n :
833+ panic (shortIWork )
834+ }
835+
836+ _ldab := n
837+ _ab := make ([]float64 , (kd + 1 )* _ldab )
838+ convDpbToLapacke (uplo , n , kd , ab , ldab , _ab , _ldab )
839+ _rcond := []float64 {0 }
840+ _iwork := make ([]int32 , n )
841+ lapacke .Dpbcon (byte (uplo ), n , kd , _ab , _ldab , anorm , _rcond , work , _iwork )
842+ return _rcond [0 ]
843+ }
844+
797845// Dpbtrf computes the Cholesky factorization of an n×n symmetric positive
798846// definite band matrix
799847// A = U^T * U if uplo == blas.Upper
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