Hi all,

I have the problem that the NViewToScale1DTransformation function is not reversible.

Following Code Snippet illustrates the problem basicaly:

NPointF viewpoint = new NPointF(x, y); 

double xValue = 0;

double yValue = 0; 

// Transformation rule to obtain the xValue

NViewToScale1DTransformation tranformX = new NViewToScale1DTransformation(_ChartControl.View.Context, _Chart, (int)StandardAxis.PrimaryX, (int)StandardAxis.PrimaryY); 

// Transformation rule to obtain the yValue

NViewToScale1DTransformation tranformY = new NViewToScale1DTransformation(_ChartControl.View.Context, _Chart, (int)StandardAxis.PrimaryY, (int)StandardAxis.PrimaryX);

NScale1DToViewTransformation tranformXRestore = new NScale1DToViewTransformation(_ChartControl.View.Context, _Chart, (int)StandardAxis.PrimaryX); 

NScale1DToViewTransformation tranformYRestore = new NScale1DToViewTransformation(_ChartControl.View.Context, _Chart, (int)StandardAxis.PrimaryY); 

// perform the transformations

tranformX.Transform(viewpoint, ref xValue);

tranformY.Transform(viewpoint, ref yValue); 

NPointF viewPoint2 = new NPointF();

NPointF viewPoint3 = new NPointF(); 

// perform the transformations backwards

tranformXRestore.Transform(xValue, ref viewPoint2);

tranformYRestore.Transform(yValue, ref viewPoint3);

When calling the method with initial ViewPoint = (82, 22), the result after NViewToScale1DTransform yields (10.21851, 149.62404)

which is correct. Transforming this back via NScale1DToViewTransform yields (-69039, 233) for viewPoint2 and (241, -89227) for 

viewPoint3. Of course I want to get the inital values (82, 22) back.

Am I missing something here? Is it even possible to retransform the way I want it to be?

Best regards,

Tobias

Hi Tobias,

Generally all transformation that map a higher dimensional space to a lower one are not reversible. Try using NScale2DToViewTransformation and NViewToScale2DTransformation they should be reversible.