Function

cblas_dgemv(_:_:_:_:_:_:_:_:_:_:_:_:)

Multiplies a matrix by a vector (double precision).

Parameters

`Order`

Specifies row-major (C) or column-major (Fortran) data ordering.

`TransA`

Specifies whether to transpose matrix `A`.

`M`

Number of rows in matrix `A`.

`N`

Number of columns in matrix `A`.

`alpha`

Scaling factor for the product of matrix `A` and vector `X`.

`A`

Matrix A.

`lda`

The size of the first dimention of matrix `A`; if you are passing a matrix `A[m][n]`, the value should be `m`.

`X`

Vector X.

`incX`

Stride within `X`. For example, if `incX` is 7, every 7th element is used.

`beta`

Scaling factor for vector `Y`.

`Y`

Vector Y

`incY`

Stride within Y. For example, if incY is 7, every 7th element is used.

Discussion

This function multiplies `A * X` (after transposing `A`, if needed) and multiplies the resulting matrix by `alpha`. It then multiplies vector `Y` by `beta`. It stores the sum of these two products in vector `Y`.

Thus, it calculates either

`Y←αAX + βY`

with optional use of the transposed form of `A`.

Double-Precision Float Matrix Functions

`func cblas_dasum(Int32, UnsafePointer<Double>!, Int32) -> Double`

Computes the sum of the absolute values of elements in a vector (double-precision).

`func cblas_dnrm2(Int32, UnsafePointer<Double>!, Int32) -> Double`

Computes the L2 norm (Euclidian length) of a vector (double precision).

`func cblas_dscal(Int32, Double, UnsafeMutablePointer<Double>!, Int32)`

Multiplies each element of a vector by a constant (double-precision).

`func cblas_dspmv(CBLAS_ORDER, CBLAS_UPLO, Int32, Double, UnsafePointer<Double>!, UnsafePointer<Double>!, Int32, Double, UnsafeMutablePointer<Double>!, Int32)`

Scales a packed symmetric matrix, then multiplies by a vector, then scales and adds another vector (double precision).

`func cblas_dspr(CBLAS_ORDER, CBLAS_UPLO, Int32, Double, UnsafePointer<Double>!, Int32, UnsafeMutablePointer<Double>!)`

Rank one update: adds a packed symmetric matrix to the product of a scaling factor, a vector, and its transpose (double precision).

`func cblas_dsyr(CBLAS_ORDER, CBLAS_UPLO, Int32, Double, UnsafePointer<Double>!, Int32, UnsafeMutablePointer<Double>!, Int32)`

Rank one update: adds a symmetric matrix to the product of a scaling factor, a vector, and its transpose (double precision).