# BLAS Level 1 Routines That Can Work With Sparse Vectors

The following BLAS Level 1 routines will give correct results when you pass to them a compressed-form array x(with the increment `incx=1)`:

?asum

  sum of absolute values of vector elements

?copy

  copying a vector

?nrm2

  Euclidean norm of a vector

?scal

  scaling a vector

i?amax

  index of the element with the largest absolute value for real flavors, or the largest sum `|Re(x(i))|+|Im(x(i))|` for complex flavors.

i?amin

  index of the element with the smallest absolute value for real flavors, or the smallest sum `|Re(x(i))|+|Im(x(i))|` for complex flavors.

The result i returned by i?amax and i?amin should be interpreted as index in the compressed-form array, so that the largest (smallest) value is x`(i)`; the corresponding index in full-storage array is `indx(i)`.

You can also call ?roti to compute the parameters of Givens rotation and then pass these parameters to the Sparse BLAS routines ?roti.

Parent topic: Sparse BLAS Level 1 Routines