I have a need to sum columns in my datastore. The same datastore is used in other places in the report so I don't want to modify it. Here is an example. My datastore has columns business component, role and wages. There are only three rows in this example. Each is for a different employee, business_component, and taxyear. I'd like to have columns in my table business component, research$,support$,superv$,totalresearch$,totalact$

"showFooter"=>"bottom",
        "columns"=>array(
            "business_component"=>array("label"=>"Business Component"),
            "a"=>array("label"=>"research$"),
            "b"=>array("label"=>"support$"),
            "c"=>array("label"=>"superv$"),

etc

Should I be using piping to create these totals within koolreport?

With much effort (a whole day) I managed to solve this. I just have one problem.

           array(
                "label"=>"Substantially All %",
                "value"=>function($row) {
                    return $row["research_dol"]/($row["research_dol"]+$row["support_dol"]+$row["supervision_dol"]);
                },
                "type"=>"number",
                "prefix"=>"%",
            )

if ($row["research_dol"]+$row["support_dol"]+$row["supervision_dol"]) equals zero, I get a divide by zero error. What can I do about this in the above structure?

Something like this?

array(
                "label"=>"POE$/total$",
                "value"=>function($row) {
                    if (($row["research_dol"]+$row["support_dol"]+$row["supervision_dol"])==0)
                         return 0;
                    else
                        return($row["research_dol"]/($row["research_dol"]+$row["support_dol"]+$row["supervision_dol"]));
                },
                "cssStyle" => "text-align:center",
                'formatValue'=>' @value %', // format to $12
                "type"=>"number",
                "prefix"=>"%",
            )

seems to work. thx