ScaleProvider that supports negative scale values for BarCharts
Hi,
You can use this ScaleProvider to manage BarChart scale to graph not only positive but negative figures, and generates integer adhoc intervals.
Code:
public class BarScaleProvider implements ScaleProvider {
public Scale calcScale(double min, double max) {
Scale result=null;
int divideCount=0;
boolean found=false;
Double interval;
Double minValue;
Double maxValue;
double offset=max - min;
if(offset>1000){
while(!found){
offset=offset / 1000;
divideCount++;
if(offset<1000)
found=true;
}
}
interval=this.getInterval(offset);
for(int i=0; i<divideCount;i++){
interval=interval*1000;
}
interval=interval.intValue()*1.0;
minValue=min;
minValue=minValue.intValue()*1.0;
maxValue=max;
maxValue=maxValue.intValue()*1.0;
Double remainder=maxValue / interval;
remainder=remainder.intValue()*1.0;
maxValue=maxValue+interval-remainder;
if(min<0.0){
minValue=0.0;
while(minValue>min){
minValue=minValue-interval;
}
}
result=new Scale();
result.setMin(minValue);
result.setMax(maxValue);
result.setInterval(interval);
return result;
}
protected double getInterval(double value){
Range[] ranges={ new Range(500, 1000, 100), new Range(200, 500, 50),
new Range(100, 200, 20) , new Range(50, 100, 10),
new Range(20, 50, 5) , new Range(10, 20, 2),
new Range(5, 10, 1) , new Range(2, 5, 0.5),
new Range(1, 2, 0.2)};
double interval=0;
for(Range r : ranges){
if(value>=r.left && value<r.right){
interval=r.interval;
break;
}
}
return interval;
}
protected class Range {
double left;
double right;
double interval;
protected Range(double left, double right, double interval){
this.left=left;
this.right=right;
this.interval=interval;
}
}
}
