This node evaluates a (free-form) mathematical expression based on
the values of the flow variables. The computed results can be either appended as
new variable or be used to replace an input variable. Commonly used functions are shown in the list
"Mathematical Functions". There are also some constants available,
such as *pi* (the ratio of the circumference of a circle
to its diameter) and *e* (the base of the natural logarithms).

This node uses *JEP*, the
Java Math Expression Parser.

You can reference the integer flow variables like this: `$${IflowVar}$$`

,
the floating point flow variables like this: `$${DflowVar}$$`

.

NaN values act as value true in boolean expressions and compared to anything (including NaN) in any way (including ==, but not !=, which is like !(... == ...)) is false (0).

*Please note the expressions are case sensitive.*

- Flow Variable List
- Available flow variables, which can be used as variables in the expression.
- Category
- The operator categories.
- Function
- A list of valid operators in the selected category.
- Description
- Short help about the operator.
- Expression
- The mathematical expression editor. You have completion available.
- Append Variable
- The name of the variable to append.
- Replace Variable
- The variable to be replaced.
- Convert to Int
- The result should be converted to an integer, or kept as a floating point number.

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To use this node in KNIME, install the extension KNIME Math Expression (JEP) from the below update site following our NodePit Product and Node Installation Guide:

v4.5

A zipped version of the software site can be downloaded here.

Do you have feedback, questions, comments about NodePit, want to support this platform, or want your own nodes or workflows listed here as well? Do you think, the search results could be improved or something is missing? Then please get in touch! Alternatively, you can send us an email to mail@nodepit.com, follow @NodePit on Twitter, or chat on Gitter!

**Please note that this is only about NodePit. We do not provide general support for KNIME — please use the KNIME forums instead.**