Developer Hooks for GravityMath

gravityview/math/table_footer_calculation/math_shortcode Modify Math shortcode parameters before calculation
gravityview/math/table_footer_calculation/calculation_result Modify calculation result
gravityview/math/table_footer_calculation/format_time_field_calculation_result Format calculation result of a time field
gravityview/math/entries/visible Modify visible entries
gravityview/math/aggregate_data/modify_field_value Modify field value used for aggregate data calculation

Since 2.0

`$entries`	array[]	Array of visible entries used to calculate the current result.
`$atts`	array	Shortcode parameters

Since 2.0

`$value`	string	Array of visible entries used to calculate the current result.
`$transform_value`	string	The transformation operation name passed via shortcode

Since 1.0

$result string Shortcode output.

Here's an example to display 0 when the calculation result is empty for some reason:

add_filter('gravityview/math/shortcode/output', function( $result) {
	return ($result === '') ? 0 : $result;
});