LinearAlgebra`BLAS`
LinearAlgebra`BLAS`

SYR

SYR[ul,α,x,a]

computes the symmetric rank-one update a+α Outer[Times,x,x] and resets the appropriate part of a to the result.

Details

  • To use SYR, you first need to load the BLAS Package using Needs["LinearAlgebra`BLAS`"].
  • The following arguments must be given:
  • ulinput stringupper/lower triangular string
    αinput expressionscalar mutliple
    xinput expressionvector
    ainput/output symbolmatrix; the symbol value is modified in place
  • The upper/lower triangular string ul may be specified as:
  • "U"update the upper triangular part of a
    "L"update the lower triangular part of a
  • Dimensions of the matrix and vector arguments must be such that the dot product and addition are well defined.

Examples

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Basic Examples  (1)

Load the BLAS package:

In[1]:=
Click for copyable input

Apply a symmetric rank-one update to the upper triangular part of a matrix:

In[2]:=
Click for copyable input
Out[2]=

Scope  (4)

Properties & Relations  (1)

Possible Issues  (2)