DGET51  generally checks a decomposition of the form


              A = U B V'


      where ' means transpose and U and V are orthogonal.


      Specifically, if ITYPE=1


              RESULT = | A - U B V' | / ( |A| n ulp )


      If ITYPE=2, then:


              RESULT = | A - B | / ( |A| n ulp )


      If ITYPE=3, then:


              RESULT = | I - UU' | / ( n ulp )

ITYPE

          ITYPE is INTEGER


          Specifies the type of tests to be performed.


          =1: RESULT = | A - U B V' | / ( |A| n ulp )


          =2: RESULT = | A - B | / ( |A| n ulp )


          =3: RESULT = | I - UU' | / ( n ulp )

N

          N is INTEGER


          The size of the matrix.  If it is zero, DGET51 does nothing.


          It must be at least zero.

A

          A is DOUBLE PRECISION array, dimension (LDA, N)


          The original (unfactored) matrix.

LDA

          LDA is INTEGER


          The leading dimension of A.  It must be at least 1


          and at least N.

B

          B is DOUBLE PRECISION array, dimension (LDB, N)


          The factored matrix.

LDB

          LDB is INTEGER


          The leading dimension of B.  It must be at least 1


          and at least N.

U

          U is DOUBLE PRECISION array, dimension (LDU, N)


          The orthogonal matrix on the left-hand side in the


          decomposition.


          Not referenced if ITYPE=2

LDU

          LDU is INTEGER


          The leading dimension of U.  LDU must be at least N and


          at least 1.

V

          V is DOUBLE PRECISION array, dimension (LDV, N)


          The orthogonal matrix on the left-hand side in the


          decomposition.


          Not referenced if ITYPE=2

LDV

          LDV is INTEGER


          The leading dimension of V.  LDV must be at least N and


          at least 1.

WORK

          WORK is DOUBLE PRECISION array, dimension (2*N**2)

RESULT

          RESULT is DOUBLE PRECISION


          The values computed by the test specified by ITYPE.  The


          value is currently limited to 1/ulp, to avoid overflow.


          Errors are flagged by RESULT=10/ulp.

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