var paper = Raphael("paper", 500, 500);

​

    var total=30;

    var center_x=200;

    var center_y=200;

    var radie=200;

    var val = 360 / total;

    for (var i=0; total>=i; i++) {

        var start=val*i;

        var gradientAngle=val*(total-i);

        var angle = (start + val % 360) * Math.PI / 180;

​

       renderPiePiece(center_x, center_y, radie, start, start+val, gradientAngle);

    }

​

    function renderPiePiece(center_x, center_y, radie, start_angle, end_angle, gradientAngle) {

        var flag = (end_angle - start_angle) > 180;

        start_angle = (start_angle % 360) * Math.PI / 180;

        end_angle = (end_angle % 360) * Math.PI / 180;

        paper

            .path(

                ["M", center_x, center_y,

                "l", radie * Math.cos(start_angle), radie * Math.sin(start_angle), 

                "A", radie, radie, 0, +flag, 1, center_x + radie * Math.cos(end_angle), center_y + radie * Math.sin(end_angle), 

                "z"]

            ).attr({

                stroke:'black',

                "stroke-width":1,

                fill:gradientAngle+'-#fff:0-#000'

            });

        }