IDAMAX(3) BLAS routine of NEC Numeric Library Collection IDAMAX(3) NAME IDAMAX - BLAS level one, maximum index function SYNOPSIS INTEGER FUNCTION IDAMAX ( n, x, incx ) INTEGER n, incx DOUBLE PRECISION x DESCRIPTION IDAMAX searches a double precision vector for the first occurrence of the the maximum absolute value. The vector x has length n and increment incx. ARGUMENTS n INTEGER. (input) Number of elements to process in the vector to be searched. If n <= 0, these routines return 0. x DOUBLE PRECISION. (input) Array of dimension (n-1) * |incx| + 1. Array x contains the vector to be searched. incx INTEGER. (input) Increment between elements of x. RETURN VALUES IDAMAX INTEGER. (output) Return the first index of the maximum absolute value of vector x. The vector x has length n and increment incx. NOTES This routine is Level 1 Basic Linear Algebra Subprograms (Level 1 BLAS). When working backward (incx < 0), each routine starts at the end of the vector and moves backward, as follows: x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1) The largest absolute value is: ABS (x(1+(index-1) * incx)) when incx > 0 ABS (x(1+(n-index) * |incx|)) when incx < 0 BLAS routine IDAMAX(3)