Scale view - line clarification

[tomislav.peran]

Hello,

I have a question about a piece of code that bothers me because I do not understand how it works. 

I have used a red pen to write my comments beneath.

Dim DrawingScale As Double 
DrawingScale = (ViewWide / oView.Width)
If DrawingScale < 1 Then -> let's say this is 0.35
	
DrawingScale = DrawingScale ^ -1 -> then this is 2.86

inc = .25 -> why is this here?

DrawingScale = Round(Round(DrawingScale, 2) / inc) * inc ---> why is this: (.../ inc) * inc

I would expect something like this:

DrawingScale = Round(Round(DrawingScale, 2) , inc) -> I would expect something like this but that makes no sense

oView.ScaleString = "1/" & DrawingScale

 Can somebody please clarify that line of code?

Tom

[WCrihfield · Accepted solution]

Hi @tomislav.peran.  I will try to explain each step of what is going on in that longest line of code.

• The innermost code is rounding the Double to 4 decimal places, which is 1 decimal place more than the end value needs to be.
• Then the next step outward is dividing that value by the 'increment' value.
• Then the remainder of that value (after the decimal place) is being dropped by rounding the value to the nearest whole number by the left most Round function.
• Then that whole number is being multiplied by the 'increment' again, to get back to the closes multiple of the 'increment' value, without any remainder.

Does that explain it OK for you?  Rounding the value off to an Imperial fraction of an inch.

[tomislav.peran]

Hi WCrihfield,

Thanks for the explanation. I broke down the code in the following way and it does what you said:

DrawingScale = (ViewWide / oView.Width) -> 0.008

DrawingScale = DrawingScale ^ -1 -> 120.550078288

DrawingScale = Round(DrawingScale, 2) -> 120.55 

DrawingScale = Round(DrawingScale / inc) -> 482

DrawingScale = DrawingScale * inc -> 120.5 

The idea of using 0.25 is to set the scale to 100, 100.25, 100.5, 100.75...I prefer a rounded scale but oke. 

It is clear now, thanks for helping out!