# Expression

Class: NodeDoubleExpression

Create a custom expression using the input values. The user can specify an arbitrary number of input values and bits, which are assigned a variable name, starting with $$a$$. At least one value is mandatory. The variable names can then be used to create an expression to be calculated.

As an example, to create a node that takes an input value $$a$$, ads it to a second input value $$b$$, and multiplies the result with $$e$$ raised to the power of an input number $$c$$, you would write:

(a+b)*e^c


Conditional statements are also possible. To return the largest value of two inputs $$a$$ and $$b$$, the following expression would be used:

if(a>b, a, b)


Special Variables:

e: The natural logarithmic base.
pi: The ratio of the circumference of a circle to its diameter.

Conditional statements and logical expressions:

if(expression, true, false): if statement with a conditional expression, and the returned value when this expression is true and false, respectively.
=, <>, <, >, ⇐, >=: Comparison operators.
and: Logical and.
or: Logical or.
xor: Logical exclusive or.
not: Logical not.

## Inputs

#### a

The default value input.

Type: Double, Required, Single

## Outputs

#### Result

The resulting value.

Type: Double

## Settings

### Display

#### Show Expression Boolean

If TRUE, the expression will be displayed beneath the node name in the process window.

#### Node Name Text

The display name of the node in the process window.

### Expression

#### Expression Text

The expression which should be calculated.

### Inputs

#### Numbers Integer

The number of input values.

#### Bits Integer

The number of input bits.

### Result

#### Set Infinity To Number

What value should Infity be set to.

#### Set Undefined Numbers To Number

What value should undefined numbers be set to.

Keywords: expression, math