# Givens Rotation (Givens Rotation) (G Dataflow)

Performs a Givens rotation on a set of two-element vectors.

## y increment

An integer that determines whether and how this node skips elements in y for the calculation.

The following table explains how this node behaves depending on the value of y increment.

Value Behavior
y increment ≥ number of elements in y Uses only the first element in y.
1 < y increment < number of element in y Uses only the elements whose indexes are multiples of the value of y increment.
y increment = 1 Does not skip any elements in y.
y increment = 0 Returns an error.
y increment < 0 Reverses the order of the elements, and then uses elements that have indexes that are multiples of the value of y increment.

Default: 1

## x increment

An integer that determines whether and how this node skips elements in x for the calculation.

The following table explains how this node behaves depending on the value of x increment.

Value Behavior
x increment ≥ number of elements in x Uses only the first element in x.
1 < x increment < number of element in x Uses only the elements whose indexes are multiples of the value of x increment.
x increment = 1 Does not skip any elements in x.
x increment = 0 Returns an error.
x increment < 0 Reverses the order of the elements, and then uses elements that have indexes that are multiples of the value of x increment.

Default: 1

## x

Vector that contains the x-components of the set of two-element vectors.

This input accepts the following data types:

• 1D array of double-precision, floating-point numbers
• 1D array of complex double-precision, floating-point numbers

## y

Vector that contains the y-components of the set of two-element vectors.

This input accepts the following data types:

• 1D array of double-precision, floating-point numbers
• 1D array of complex double-precision, floating-point numbers

## c

c parameter of the Givens rotation.

You can use Givens Rotation (Givens Rotation Parameters) to obtain a value for this input.

Default: 1

## s

s parameter of the Givens rotation.

You can use Givens Rotation (Givens Rotation Parameters) to obtain a value for this input.

Default: 0

## 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

## drot x

Vector that contains the x-components of the set of two-element vectors after the rotation.

This output is available only if you wire a 1D array of double-precision, floating-point numbers to x or y.

## zdrot x

Vector that contains the x-components of the set of two-element vectors after the rotation.

This output is available only if you wire a 1D array of complex double-precision, floating-point numbers to x or y.

## drot y

Vector that contains the y-components of the set of two-element vectors after the rotation.

This output is available only if you wire a 1D array of double-precision, floating-point numbers to x or y.

## zdrot y

Vector that contains the y-components of the set of two-element vectors after the rotation.

This output is available only if you wire a 1D array of complex double-precision, floating-point numbers to x or y.

## 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.

## Algorithm for Performing Givens Rotation

If you set both x increment and y increment to 1, this node performs Givens Rotation according to the following equation:

$\left[\begin{array}{c}{drot\text{\hspace{0.17em}}x}_{i}\\ {drot\text{\hspace{0.17em}}y}_{i}\end{array}\right]=\left[\begin{array}{cc}c& s\\ -s& c\end{array}\right]*\left[\begin{array}{c}{x}_{i}\\ {y}_{i}\end{array}\right]$

where

• xi is the ith element of x
• yi is the ith element of y
• drot xi is the ith element of drot x
• drot yi is the ith element of drot y
• c and s are the Givens rotation parameters c and s

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

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