- #1

tarekph

- 1

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I am a beginner in programming with Fortran and I want to use the LAPACK DSYEV in my program.

I am an example to determine the eigenvalues of a matrix (3x3) after I use it in my program but when I compile I get this error

"" "" "** One entry to DSYEV parameter number 5 Had an illegal value" "" ""

Here is my example:

Program eigenvalue

implicit none

! statements

double precision :: A (3.3), w (3), Work (3)

integer :: i INFO, LWORK, LDA = 3

character :: N, U

! A matrix

A (1 : ) = (/ 3, 1, 3 /)

A (2, : ) = (/ 1, 5, 6 /)

A (3 : ) = (/ 3, 6, 5 /)

CALL DSYEV ('N', 'U', 3, Q, W, LDA, WORK, LWORK, INFO)

! print the solution

do i = 1, 3

write (*, 9) i, w (i)

end do

9 format ('x [' i1 '] =', f5.2)

end programs eigenvalue

I know not how I met the LDA or WORK .. LWORK...

thank you