Time series rent BT

From JSXGraph Wiki
Revision as of 08:40, 15 August 2012 by Michael (talk | contribs)
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Average rent in BT city for flats of size [math]\displaystyle{ 76-100m^2 }[/math] from 2004 to 2011

The underlying JavaScript code

var toDate = function(datestr) {
        var a = datestr.split('.');
        return new Date(a[2]*1,a[1]*1-1,a[0]*1);
    };

var table = [ 
['1.1.2004', 5.35],
['1.1.2005', 5.37],
['1.1.2006', 5.48],
['1.1.2007', 5.32],
['1.1.2008', 5.30],
['1.1.2009', 5.37],
['1.1.2010', 5.59],
['1.1.2011', 5.81]   ];

var plotChartGoogleStyle = function(board, x, y, axisHeight) {
    var points = [], i, p;
    board.suspendUpdate();
    points.push(board.createElement('point', [0, axisHeight], {visible:false, name:'', fixed:true, withLabel:false})); 
    for (i=0;i<x.length;i++) { 
        p = board.create('point', [x[i],y[i]], 
                   {strokeWidth:2, strokeColor:'#ffffff', 
                    highlightStrokeColor:'#0077cc', fillColor:'#0077cc',  
                    highlightFillColor:'#0077cc', style:6, name:'', fixed:true});
        points.push(p);
    }
    points.push(board.create('point', [x[x.length-1],axisHeight], {visible:false, name:'', fixed:true})); 
 
    // Filled area. We need two additional points [start,axisHeight] and [end,axisHeight]
    board.create('polygon',points, {withLines:false,
                   fillColor:'#e6f2fa',withLabel:false});
 
    // Curve:
    var c = board.create('curve', [x,y], 
                 {strokeWidth:3, strokeColor:'#0077cc', 
                  highlightStrokeColor:'#0077cc'}
               ); 
    board.unsuspendUpdate();

return c;
};

var i, x = [], y = [], 
    birthday = toDate(table[0][0]);

var brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-1,10,15,-1]});
brd.create('axis',[[0,0],[1,0]]);
brd.create('axis',[[0,0],[0,1]]);

brd.highlightInfobox = function(x,y,el) {
  var te = table[Math.floor(x)];
console.log(x);
  this.infobox.setText('<span style="color:black;font-weight:bold">' + (te ? te[0] : (Math.floor(x) == 8 ? '1.1.2012' : '1.1.2013')) + ', ' + y + ' EUR/m^2</span>');
  this.infobox.rendNode.style.border = 'groove ' + el.visProp['strokecolor'] + ' 2px';
  this.infobox.rendNode.style.padding = '5px';
  this.infobox.rendNode.style.backgroundColor = 'white';
}

// Transform the dates into years from start
for (i=0;i<table.length;i++) {
    x[i] = Math.round(((toDate(table[i][0])).getTime()-birthday.getTime())/(1000.0*60.0*60.0*24.0*365.));
    y[i] = table[i][1]*1;
}

var ts = plotChartGoogleStyle(brd,x,y,0);

var reg = brd.create('functiongraph',[JXG.Math.Numerics.regressionPolynomial(2,x,y)],{strokeColor:'black',dash:3});     

var line2012 = brd.create('line', [[8, 0], [8, 2]], {strokeColor: 'black', strokeWidth: 2, withLabel: false, visible: false});
var indicator2012 = brd.create('intersection', [line2012, reg], {withLabel: false, color: 'black', size: 3});

var line2013 = brd.create('line', [[9, 0], [9, 2]], {strokeColor: 'black', strokeWidth: 2, withLabel: false, visible: false});
var indicator2013 = brd.create('intersection', [line2013, reg], {withLabel: false, color: 'black', size: 3});