• In v2.22.0,
  • Fixed an issue with a sum column encountering a cell without a defined "data-math" attribute returning an empty string instead of zero. See issue #873.
  • Fixed a javascript error occurring on empty tables & now all updates will reapply column indexing to tbody cells - I know this isn't ideal as it would be slow on larger tables.
• In v2.19.1, added math_event option & fixed an issue with event unbinding in jQuery version < 1.9.
• In v2.17.1,
  • Values added to the data-attribute set by the textAttribute option will now be used in the calculation instead of the actual cell content.
  • The Grand Total cells now shows a higher precision value to emphasize this point.
• In v2.16.4, added:
  • Two new options: math_prefix and math_suffix, which will be added before or after the prefix or suffix, respectively.
  • Added "Mask Examples" section with examples, and how to use the $.tablesorter.formatMask function.
  
  
• This widget will only work in tablesorter version 2.16+ and jQuery version 1.7+.
• It adds basic math capabilities. A full list of default formulas is listed in the "Attribute Settings" section.
• Add your own custom formulas which manipulating an array of values gathered from the table by row, column or a column block (above).
• This is by no means a comprehensive widget that performs like a spreadsheet, but you can customize the data gathering "type" and available "formula", as desired.
• The widget will update the calculations based on filtered rows, and will update if any data within the table changes (using update events).
• This widget is not optimized for very large tables, for two reasons:
  • On initialization, it cycles through every table row, calculates the column index, and adds a data-column attribute.
  • It uses the update method whenever it recalculates values to make the results sortable. This occurs when any of the update methods are used and after the table is filtered.
• When setting tablesorter's debug option to true, this widget will output each {type}-{formula} value found, the array of numbers used and the result.

Math widget default options (added inside of tablesorter widgetOptions)

// column index(es) to ignore
math_ignore : [0,1]

<th data-math="all-sum" data-math-mask="##0.00">all-sum</th>

// complete executed after each function
math_complete : function($cell, wo, result, value, arry){
    return '$ ' + result + $cell.attr('data-suffix');
}

math_complete : function($cell, wo, result, value, arry){
    var percent = Math.round( value * 1e4 ) / 100; // percent with two decimal places
    return $.tablesorter.formatMask( wo.math_mask, percent ) + ' %';
}

<td data-math="{type}-{formula}"></td>

{type} (data gathering)

• row - gather the table cell values from the same row as the data-math attribute.
• above - gather the table cell values from the same column as the data-math attribute, but stop when the first table cell is reached, or when another cell with a data-attribute with an "above" type is reached; see the first table demo below to see why this is useful.
• col - gather the table cell values from the same column as the data-math attribute.
• all - gather all table cell values with a data-math attribute that start with "all".

{formula} (defaults)

• count - returns the count (length) of the data set.
• sum - returns the sum of all values in the data set.
• max - returns the maximum value in the data set.
• min - returns the minimum values in the data set.
• mean - returns the mean (average) of all values in the data set; it uses the sum formula in part of the calculation.
• median - returns the median (middle value) of the data set.
• mode - returns an array of the mode(s) (most frequent value or values) in the data set; an array is always returned, even if only one mode exists (see the second demo below).
• range - returns the range (highest minus lowest value) of the data set.
• varp - returns the variance of the data set (population).
• vars - returns the variance of the data set (sample).
• stdevp - returns the standard deviation of the data set (population).
• stdevs - returns the standard deviation of the data set (sample).
• custom (not a default)
  • Custom formulas can have any name
  • Return your result after making whatever calculation from the array of data passed to the formula
  • For example:

    // adding a custom equation... named "product"
    // access from data-math="row-product" (or "above-product", or "col-product")
    $.tablesorter.equations['product'] = function(arry) {
        // multiple all array values together
        var product = 1;
        $.each(arry, function(i,v){
            // oops, we shouldn't have any zero values in the array
            if (v !== 0) {
                product *= v;
            }
        });
        return product;
    };

Ignoring cells

• Entire row: if the <tr> math data-attribute contains the keyword "ignore" then that entire row of cells will be skipped when building the array of data to be used for calculations.

  <tr data-math="ignore"><td>1</td><td>2</td><td>3</td></tr>

• Cell: if the table cell math data-attribute contains the keyword "ignore" then that cell will be skipped when building the array of data to be used for calculations.

  <td data-math="ignore">1</td>

• Column: set the widget math_ignore option with an array of zero-based column indexes of columns to ignore or skip when building the array of data for calculations.

  math_ignore : [0,1]

// $.tablesorter.formatMask(mask, value, prefix, suffix);
$.tablesorter.formatMask('$#,##0.00 USD', 12345.678, 'prefix ', ' suffix');
// result: "prefix $12,345.68 USD suffix"

• The $.tablesorter.formatMask function has the following parameters:
  • mask - please refer to the math_mask option for more details.
  • value - number to be formatted.
  • prefix - please refer to the math_prefix option for more details (v2.16.4).
  • suffix - please refer to the math_suffix option for more details (v2.16.4).

Experiment with the mask: