The FORTRAN call
CALL DSYMV( "L", N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )becomes the C call
PLA_dsymv( "L", &n, &alpha, a, &lda, x, &incx, &beta, y, &incy );Recall that only the first character of the string parameter is checked. Thus "L" is equivalent to "Lower triangular".