Must be

'U'

or

'L'

or

'F'

.

If

uplo

=

'U'

,

a

stores the upper triangular parts of

A

.

If

uplo

=

'L'

,

a

stores the lower triangular parts of

A

.

If

uplo

=

'F'

,

a

stores the full matrix

A

.

Sets the size of the problem.

n

> 0.

Array of dimension

lda

by

n

, contains either full matrix

A

or upper or lower triangular part of the matrix

A

, as specified by

uplo

The leading dimension of the array

a

. Must be at least max(1,

n

).

Array, dimension of 128. This array is used to pass various parameters to Extended Eigensolver routines. See Extended Eigensolver Input Parameters for a complete description of the parameters and their default values.

The lower and upper bounds of the interval to be searched for eigenvalues;

emin

≤

emax.

On entry, specifies the initial guess for subspace dimension to be used,

0 <

m0

≤

n

. Set

m0

≥

m

where

m

is the total number of eigenvalues located in the interval [

emin

,

emax

]. If the initial guess is wrong, Extended Eigensolver routines return

info

=3.

On entry, if

fpm

[4]

=1, the array

x

of size

n

by

m

contains a basis of guess subspace where

n

is the order of the input matrix.

On output, contains the relative error on the trace: |

trace

i

-

trace

i-1

| /max(|

emin

|, |

emax

|)

On output, contains the number of refinement loop executed. Ignored on input.

Array of length

m0

. On output, the first

m

entries of

e

are eigenvalues found in the interval.

On output, the first

m

columns of

x

contain the orthonormal eigenvectors corresponding to the computed eigenvalues

e

, with the

i

-th column of

x

holding the eigenvector associated with

e

[

i

]

.

The total number of eigenvalues found in the interval [

emin

,

emax

]: 0 ≤

m

≤

m0

.

Array of length

m0

. On exit, the first

m

components contain the relative residual vector:

for

i

=1, 2, …,

m

, and where

m

is the total number of eigenvalues found in the search interval.

If

info

=0, the execution is successful. If

info

≠ 0, see Output Eigensolver info Details.