Math Formula

This node evaluates a mathematical expression based on the values in a row. The computed results can be either appended as new column or be used to replace an input column. Available variables are the values in the corresponding row of the table (left list in the dialog). 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), e (the base of the natural logarithms), the total number of rows in the table, and some other column based constants (constant category of functions).

This node uses JEP, the Java Math Expression Parser.

Column based constants such as COL_MIN(col_name) will be calculated in advance (if necessary).

You can reference the integer flow variables like this: $${IflowVar}$$, the floating point flow variables like this: $${DflowVar}$$.

Reference the columns with the form: $colName$

When any of the used columns contains a missing value, the result is missing, just like when the result would be NaN, infinite value, or outside of the 32 bit signed integer range when that is requested.

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.

Options

Column List
Available numerical columns, which can be used as variables in the expression.
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 Column
The name of the column to append.
Replace Column
The column to be replaced.
Convert to Int
The result should be converted to an integer, or kept as a floating point number.

Input Ports

Icon
Any input data

Output Ports

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Input data amended with math column.

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