Math Field

The Math Field module defines a new field type to dynamically calculate values on entity forms. This is an alternative to Computed Field
that does not require the use of PHP Filter.

Math expression fields are dynamically updated via ajax on the entity form as soon as all necessary fields are populated. If JavaScript is disabled, the field will be evaluated when the form is submitted. The result is stored in the database when the form is submitted.

Math Field uses the cTools math expression library and supports all the basic operators (+-*/^) as well as constants 'pi' and 'e' and the following functions:

    sin(), sinh(), arcsin(), asin(), arcsinh(), asinh(),
    cos(), cosh(), arccos(), acos(), arccosh(), acosh(),
    tan(), tanh(), arctan(), atan(), arctanh(), atanh(),
    pow(), exp(), sqrt(), abs(), ln(), log(), time(), 
    ceil(), floor(), min(), max(), round()

You can also define and evaluate your own functions separated by a ';'. For example:

    f(x) = x + 2; f(3)

Other fields may be included in math expressions using tokens with the structure [$field_name:$delta:$column] where $field_name is the machine name of a supported field, $delta is the index for multivalue fields ($delta begins with 0), and $column is the column name for multicolumn fields. $delta and/or $column may be omitted if the field only has one value or column respectively.

Out of the box, Math Field supports the following field types:

• Integer and List (integer)
• Float and List (float)
• Decimal

Modules that define their own fields types may add support for Math Field by implementing hook_mathfield_get_token() and hook_mathfield_get_token_value().

Requirements

This module requires the following modules:

• Field (core)
• cTools (https://www.drupal.org/project/ctools)

Known issues and roadmap

• The cTools math expression library causes an error when using function that take more than one parameter. This effects pow(), min(), max(). See #1958538: Improve math expression engine.
• Math Field does not yet support multivalue options fields (checkboxes, or multiselect). See #2483453: Add aggregate functions for multivalue fields.
• Math Field does not yet support Field Collections. See #2573643: Support the Field Collection module.

Credits

Originally developed by Monarch Digital for SIGMAXIM.