# Evaluate Parametric Equation (X-Y-Z(a,t1,t2)) (G Dataflow)

Describes a surface in 3D with two independent variables running over two different intervals.

You can integrate an arbitrary set of parameters in the formula.

## number of points

Numbers of values for both variables used in the function calculation.

## formulas

An array of three strings describing three functions, each of the which represents a component of the surface that this node describes. 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.

Example of Entering Values for formulas

As an example, consider the ellipsoid given by

$\frac{{x}^{2}}{{a}^{2}}+\frac{{y}^{2}}{{b}^{2}}+\frac{{z}^{2}}{{c}^{2}}=1$

Setting the parameter values in parameters as a = 1, b = 2, and c = 3, you can enter the following three equations in formulas to get x, y, and z values of the ellipsoid:

a*cos(x1)

b*sin(x1)*sin(x2)

c*sin(x1)*cos(x2)

where x1 and x2 are the two specified variables.

## start

Start values of the variables in the interval where this node starts calculating values.

This input can contain only two elements. Otherwise, this node returns an error.

Default: [0.00, 0.00]

## end

End values of the variables in the interval where this node stops calculating values.

This input can contain only two elements. Otherwise, this node returns an error.

Default: [1.00, 1.00]

## variables

Names of the variables.

Variable names must start with a letter or an underscore followed by any number of alphanumeric characters or underscores.

## 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

## parameters

Variables and their corresponding values in the parameters.

### variable

Name of the parameter that uses the conventions of the Parsing nodes.

Default: Empty string

### value

Value of variable.

Default: 0

## exclude end

Boolean that specifies whether this node uses the end value of the interval when calculating function values.

 True Does not use the end value when calculating function values. False Uses the end value when calculating function values.

Default: False

## x

x values at the grid points.

These values are calculated on a 2D grid defined by the discrete values of variables. The number of elements in x equals to the product of the numbers of the two elements in number of points.

## y

y values at the grid points.

These values are calculated on a 2D grid defined by the discrete values of variables. The number of elements in y equals to the product of the numbers of the two elements in number of points.

## z

z values at the grid points.

These values are calculated on a 2D grid defined by the discrete values of variables. The number of elements in z equals to the product of the numbers of the two elements in number of points.

## 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