Use ActionScript to calculate the scale in IMS

// Scale of the graph
Public Function get mapscale (): Number
{
VaR dpixelsperinches: Number = 97.69230769;
VaR dpixelspermiles: Number = 63360 * dpixelsperinches;
VaR dpixelsperfeet: Number = 12.0 * dpixelsperinches;
VaR dpixelsperkilometers: Number = 39370.07874016 * dpixelsperinches;
VaR dpixelspermeters: Number = 39.37007874 * dpixelsperinches;
VaR dpixelspercentimeters: Number = 0.39370079 * dpixelsperinches;
Return this. currentextent. width/(this. displaytrans. imgdescriptor. imageextent. width/dpixelspermeters );
}
VaR dpixelsperinches: Number = 97.69230769;
I don't know how this 97.69230769 came from. I always feel that the size of the display is related to the resolution. Can someone tell me how to do it?