Animated age pyramid

This animation shows data from the 12th coordinated Population Projection from the "Statistisches Bundesamt (destatis)". A much more elaborate version programmed by destatis can be seen on their webpage.

 

 

How to create this animation

• Download the data from destatis.de
• Save the table which should be displayed as csv file.
• Transform the csv file into a JavaScript file containing a 2 dimensional array:

dataV1W1EJ = [["2009"," ","m"," 40 070 ","  341 ","  350 ","  353 ","  348 ",...,"  2 "],
["    "," ","w"," 41 665 ","  323 ","  333 ","  335 ","  329 ",...,"  12 "],
["    "," ","i"," 81 735 ","  663 ","  683 ","  688 ","  677 ",...,"  13 "],
["2010"," ","m"," 39 987 ","  339 ","  341 ","  350 ","  353 ",...,"  2 "],
   .
   .
   .
[" "," ","i"," 64 651 ","  465 ","  470 ","  476 ","  481 ",...,"  169 "]];

Every third row labeled by 'i' in the third column will be deleted later on.

• Now read the data

function readFile(dataArr) {
    var len = dataArr.length, 
        i, male, female, y,
        data = [];
    for (i=len-1;i>=0;i--) {
        if (i%3==2) {
            dataArr.splice(i,1);
        } else {
            if (i%3==1) {
                female = dataArr[i][3].replace(/ /g,'')*1;
            } else if (i%3==0) {
                y = dataArr[i][0]*1;
                male = dataArr[i][3].replace(/ /g,'')*1;
                data.push([y,male,female]);
            } 
            dataArr[i].splice(0,4); // year,'',m/w,no,
        }
    }
    data.reverse();
    ages = JXG.Math.Matrix.transpose(dataArr);
    return {matrix:ages, total: data};
};
var stat1 = readFile(dataV1W1EJ);

• Create the filled rectangles (men, women)

brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-850,110,850,-10],axis:false});
createCurves(stat1,brd,'#658cb2','#b23f8c');

The complete JavaScript code

<script type="text/javascript" src="/ajax/ageV1W1EJ.js"></script>
<jsxgraph width="500" height="500">
var i, t = '', yearIndex = 0, brd;
var stat1 = readFile(dataV1W1EJ);

function readFile(dataArr) {
    var len = dataArr.length, 
        i, male, female, y,
        data = [];
    for (i=len-1;i>=0;i--) {
        if (i%3==2) {
            dataArr.splice(i,1);                  //delete redundant row
        } else {
            if (i%3==1) {
                female = dataArr[i][3].replace(/ /g,'')*1;  
            } else if (i%3==0) {
                y = dataArr[i][0]*1;
                male = dataArr[i][3].replace(/ /g,'')*1;
                data.push([y,male,female]);
            } 
            dataArr[i].splice(0,4); // year,'',m/w,no,
        }
    }
    data.reverse();
    ages = JXG.Math.Matrix.transpose(dataArr);
    return {matrix:ages, total: data};
};

brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-850,110,850,-10],axis:false});
function createCurves(stat,brd, c1, c2) {
    var i, m = [], w = [],
        op = 1,
        off = 80,
        len = stat.matrix.length;
    for (i=0;i<len;i++) {
        m[i] = brd.create('curve',[[0],[0]],
                {fillColor:c1,strokeColor:c1,
                strokeOpacity:op,fillOpacity:op,
                strokeWidth:1,
                highlightFillColor:'yellow',highlightStrokeColor:'yellow'});
        m[i].updateDataArray = (function(xArr, y) { return function() {
                this.dataX = [-off,-off-xArr[2*yearIndex]*1,-off-xArr[2*yearIndex]*1,-off,-off];
                this.dataY = [y,y,y+1,y+1,y];
            }; })(stat.matrix[i], i);
        JXG.addEvent(m[i].rendNode, 'mouseover', 
            (function(g){ return function(){
                                g.highlight(); w[g._number].highlight(); setText(g._number);
                            };})(m[i]), m[i]);
        JXG.addEvent(m[i].rendNode, 'mouseout', 
            (function(g){ return function(){
                                g.noHighlight(); w[g._number].noHighlight(); 
                            };})(m[i]), m[i]);
        m[i].hasPoint = function(){return false;};
        m[i]._number = i;
    
        w[i] = brd.create('curve',[[0],[0]],
                {fillColor:c2,strokeColor:c2,
                strokeWidth:1,
                strokeOpacity:op,fillOpacity:op,
                highlightFillColor:'yellow',highlightStrokeColor:'yellow'});
        w[i].updateDataArray = (function(xArr, y) { return function() {
                this.dataX = [off,off+xArr[2*yearIndex+1]*1,off+xArr[2*yearIndex+1]*1,off,off];
                this.dataY = [y,y,y+1,y+1,y];
            }; }    )(stat.matrix[i], i);
        JXG.addEvent(w[i].rendNode, 'mouseover', 
            (function(g){ return function(){
                                g.highlight(); m[g._number].highlight(); setText(g._number);
                            };})(w[i]), w[i]);
        JXG.addEvent(w[i].rendNode, 'mouseout',  
            (function(g){ return function(){
                                g.noHighlight(); m[g._number].noHighlight();
                            };})(w[i]), w[i]);
        w[i].hasPoint = function(){return false;};
        w[i]._number = i;
        
    }
    var t = brd.create('turtle',[],{strokeColor:'#999999', highlightStrokeColor:'#999999'}); t.ht().pu().rt(90);
    for (i=0;i<=90;i+=10) { 
        t.moveTo([-750,i]).penDown().forward(750-off+10).penUp();
        t.moveTo([off-10,i]).penDown().forward(750-off+10).penUp();
        brd.create('text',[-15,i,i.toFixed(0)]);
    }
    return [m,w];
};

brd.suspendUpdate();
createCurves(stat1,brd,'#658cb2','#b23f8c');
brd.create('text',[-300,45,'men']/*,{strokeColor:'white',fontSize:20}*/);
brd.create('text',[200,45,'women']/*,{strokeColor:'white',fontSize:20}*/);
brd.unsuspendUpdate();

function changeYear() {
    yearIndex = document.getElementById('years').selectedIndex;
    setTextYear();
    brd.update();
};

function setText(n) {
    var age = n,
        male = ages[n][2*yearIndex]*1,
        female = ages[n][2*yearIndex+1]*1;
    textout.innerHTML = 'age:'+age+
                        ', born in '+(2009+yearIndex-age)+
                        '<br> male:'+male+
                        ', female:'+female+
                        ', together:'+(male+female)+
                        ' (thousand)<br> ratio w/m:'+(female/male).toFixed(2);
};
function setTextYear() {
    var n = yearIndex,
        data = stat1.total;
    textout2.innerHTML = 'Year:'+data[n][0]+
                        '<br> male:'+data[n][1]+
                        ', female:'+data[n][2]+
                        ', together:'+(data[n][1]+data[n][2])+
                        ' (million)<br> ratio w/m:'+(data[n][2]/data[n][1]).toFixed(3);
};

function animation() {
    yearIndex = (yearIndex+1)%52;
    document.getElementById('years').selectedIndex = yearIndex;
    setTextYear();
    brd.update();
    animate = setTimeout(animation,500);
};

function player(){
    if (!animate) {
        document.getElementById('playbutton').value = 'stop';
        animation();
    } else {
        document.getElementById('playbutton').value = 'play';
        clearTimeout(animate);
        animate = null;
    }
};
</jsxgraph>

<form><select id="years" onChange="changeYear()"></select>
<input type="button" id="playbutton" value="play" onClick="player();">
</form>
<div id="output2" style="padding:20px; background-color:#bbbbbb; width:500px; font-family:Arial,Helvetica">&nbsp; </div>
<div id="output" style="padding:20px; background-color:#dddddd; width:500px; font-family:Arial,Helvetica"> &nbsp;</div>
<script type="text/javascript">
    var textout = document.getElementById('output');
    var textout2 = document.getElementById('output2');
    var animate = null;
    selectYear = document.getElementById('years');
    var opt;
    for (i=2009;i<=2060;i++) {
       opt = document.createElement('option');
       opt.text = i;
       try {
          selectYear.add(opt,null);
       } catch(e) {
          selectYear.add(opt); // IE
       }
    }
    setTextYear();

</script>