lapack: add SchurComp and SchurUpdateComp types and consts

lapack/lapack.go

@@ -188,6 +188,23 @@ const (
 	EigenvaluesAndSchur SchurJob = 'S'
 )
 
+// SchurComp specifies whether and how the Schur vectors are computed in Dhseqr.
+type SchurComp byte
+
+const (
+	SchurNone SchurComp = 'N' // Schur vectors are not computed.
+	SchurHess SchurComp = 'I' // Schur vectors of the upper Hessenberg marix are computed.
+	SchurOrig SchurComp = 'V' // Schur vectors of the original matrix are computed.
+)
+
+// SchurUpdateComp specifies whether the matrix of Schur vectors is updated in Dtrexc.
+type SchurUpdateComp byte
+
+const (
+	SchurUpdate     SchurUpdateComp = 'V' // The matrix of Schur vectors is updated.
+	SchurUpdateNone SchurUpdateComp = 'N' // The matrix of Schur vectors is not updated.
+)
+
 // EVSide specifies what eigenvectors are computed in Dtrevc3.
 type EVSide byte