# Matrix Update (Symmetric » Rank-2) (G Dataflow)

Calculates the rank-2 update of the upper or lower triangular component of a symmetric matrix.  ## x

N-element vector. ## y

Input vector.

y must be the same size as x. ## A

Symmetric matrix.

A must have dimensions greater than or equal to N × N, where N is the number of elements in x. If A is an empty matrix, this node initializes A to be an N × N matrix with all elements set to 0. ## matrix A type

Triangular component of A that this node uses for the calculation.

Name Value Description
Lower Triangular 2 Uses the lower triangular component of A for the calculation.
Upper Triangular 3 Uses the upper triangular component of A for the calculation.

Default: Upper Triangular ## error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error  If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error ## alpha

Scalar that scales x * yT and y * xT, where xT and yT represent x transposed and y transposed, respectively.

Default: 1 ## dsyr2

Matrix of the same dimensions as A.

For elements in the first N rows and N columns of the triangular component you select in matrix A type, dsyr2 returns the result of alpha * x * yT + alpha * y * xT + A, where xT and yT represent x and y transposed, respectively. For any remaining elements, dsyr2 returns the value of the element in A with the same index. ## error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error  If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application