highchart autoupdate(addpoint) cause corrupted chart view - highcharts

Question

Im using multiple highchart chart inside my page and i use addpoint function to update the chart.
the problem is after some time the chart will be compressed into less than a half of original chart size.
i captured my screen which could be found here for make the problem clear:
http://www.screenr.com/f3E7
sample chart generation code:
$(function () {
$(document).ready(function() {
Highcharts.setOptions({
global: {
useUTC: false
}
});
//var chart;
chart = new Highcharts.Chart({
chart: {
renderTo: 'ch_trafficio',
type: 'spline',
marginRight: 10,
events: {
load: function() {
// set up the updating of the chart each second
var series = this.series[0];
var series1= this.series[1];
}
}
},
title: {
text: ''
},
xAxis: {
type: 'datetime',
tickPixelInterval: 150
},
yAxis: {
title: {
text: 'Value'
},
plotLines: [{
value: 0,
width: 1,
color: '#808080'
}]
},
tooltip: {
formatter: function() {
return '<b>'+ this.series.name +'</b><br/>'+
Highcharts.dateFormat('%Y-%m-%d %H:%M:%S', this.x) +'<br/>'+
Highcharts.numberFormat(this.y, 2);
}
},
plotOptions : {
area : {
lineWidth : 1,
marker : {
enabled : false,
states : {
hover : {
enabled : true,
radius : 5
}
}
},
shadow : false,
states : {
hover : {
lineWidth : 1
}
}
}
},
legend: {
enabled: true
},
exporting: {
enabled: true
},
series: [{
name: 'InBound',
type : "area",
color: '#89A54E',
data: (function() {
// generate an array of random data
var data = [],
time = (new Date()).getTime(),
i;
for (i = -119; i <= 0; i++) {
data.push({
x: time + i * 1000,
y: Math.random()
});
}
return data;
})()
},{
name: 'OutBound',
type : "area",
color: '#AA4643',
data: (function() {
// generate an array of random data
var data = [],
time = (new Date()).getTime(),
i;
for (i = -119; i <= 0; i++) {
data.push({
x: time + i * 1000,
y: Math.random()
});
}
return data;
})()
}
]
});
chart update functions:
chart.series[0].addPoint([x,data.oid1], false, true);
chart.series[1].addPoint([x,data.oid2], true, true);
chart1.series[0].addPoint([x,data.oid5], true, true);
chart2.series[0].addPoint([x,data.oid3], false, true);
chart2.series[1].addPoint([x,data.oid4], true, true);
chart3.series[0].addPoint([x,data.oid7], true, true);
thanks in advance

Answer 1

you need to add a shifting parameter for your points to shift over the chart
var series = chart.series[0],
shift = series.data.length > 100; // shift if the series is longer than 100
and to change adding point like below
chart.series[0].addPoint([x,data.oid1], true, shift);
example here