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

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

Operation this node performs on A and B.

Name Value Description
Direct 0 op(A) = A and op(B) = B
Conjugated and Transposed 1 op(A) = conjugate transpose of A and op(B) = conjugate transpose of B
Transposed 2 op(A) = transpose of A and op(B) = transpose of B

Default: Direct ## A

Matrix such that op(A) has dimensions N × K.

This input accepts the following data types:

• 2D array of double-precision, floating-point numbers
• 2D array of complex double-precision, floating-point numbers ## B

Matrix such that op(B) has the same dimensions as op(A).

This input accepts the following data types:

• 2D array of double-precision, floating-point numbers
• 2D array of complex double-precision, floating-point numbers ## C

Symmetric matrix.

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

This input accepts the following data types:

• 2D array of double-precision, floating-point numbers
• 2D array of complex double-precision, floating-point numbers ## matrix C type

Triangular component of C this node uses for the calculation.

Name Value Description
Lower Triangular 2 This node uses the lower triangular component of C for the calculation.
Upper Triangular 3 This node uses the upper triangular component of C 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 op(A) * op(B)T + op(B) * op(A)T, where op(A)T and op(B)T represent op(A) and op(B) transposed, respectively.

This input accepts the following data types:

• Double-precision, floating-point numbers
• Complex double-precision, floating-point numbers

Default: The default value is 1 if alpha is a double-precision, floating-point number. The default value is 1+0i if alpha is a complex double-precision, floating-point number. ## beta

Scalar that scales C.

This input accepts the following data types:

• Double-precision, floating-point numbers
• Complex double-precision, floating-point numbers

Default: The default value is 1 if beta is a double-precision, floating-point number. The default value is 1+0i if beta is a complex double-precision, floating-point number. ## dsyr2k

Matrix of the same dimensions as C.

For the elements in the first N rows and N columns of the triangular component you select in matrix C type, dsyr2k returns the result of the following equation:

dsyr2k = alpha * op(A) * op(B)T + alpha * op(B) * op(A)T + beta * C

For any other elements, dsyr2k returns the value of the element in C with the same index.

This output is available only if you wire a 2D array of double-precision, floating-point numbers to A, B, or C. ## zsyr2k

Matrix of the same dimensions as C.

For the elements in the first N rows and N columns of the triangular component you select in matrix C type, zsyr2k returns the result of the following equation:

zsyr2k = alpha * op(A) * op(B)T + alpha * op(B) * op(A)T + beta * C

For any other elements, zsyr2k returns the value of the element in C with the same index.

This output is available only if you wire a 2D array of complex double-precision, floating-point numbers to A, B, or C. ## 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