# Evaluate Formula (Multi-Variable Array) (G Dataflow)

Version:
Last Modified: February 27, 2020

Calculates the values of a given function at an arbitrary set of n-dimension points.  ## formula

Formula that defines the n-dimensional function. The formula can contain any number of valid variables.

Entering Valid Variables

This node accepts variables that use the following format rule: variables must start with a letter or an underscore followed by any number of alphanumeric characters or underscores. ## x values

A 2D array of x values.

The i th row of the array contains the fixed values of the i th variable of the n-dimensional function. The other dimension of the array marks the n-dimension points at which this node calculates function values. ## variables

Variable names of the n-dimension independent terms. ## 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 ## y values

Calculated function values. Each element of y values corresponds to the corresponding column of x values.

Algorithm for Calculating y values

This node calculates y values using the following equation:

y i = f(x 1i , x 2i , …, x n i )

where

• n is the number of dimensions of the given set of points
• f is an n-dimensional function given by the formula
• x 1, x 2, …, x n are n independent variables ## 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.

The following table shows an example of the inputs and outputs of this node.

formula x values variables y values
3 * x1 + 4 * x2 + x3 ^ 2 [1, 0; -1, 4; 2, 1] [x1, x2, x3] [3,17] Note

In x values, [1, -1, 2] are the values for [x 1, x 2, x 3] in the first iteration; [0, 4, 1] for the second.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

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