ArcCalc problem with 180 degrees arc

[Ruben DF]

Hi again,

I was trying to solve the problem of ArcCalc. I realized when ArcCalc is 180 degrees (PI radians) this turn up and down in a random way when i zoom the map. I don´t know why it happens, but if I create with smaller arc (176 degrees for example) this does not happen. (with 177 degrees does). is it an openmap bug?

Thanks in advance
Regards

[Don Dietrick]

Hi Ruben,

It's probably a bug, and I say probably because you are using ArcCalc  
in a more vigorous way than we originally did, which was for static  
map images (no zooming) and for arcs less than 180.  I would guess  
that the trigonometry functions used in ArcCalc are giving  
indeterminate answers for direction when the angle is PI or close to  
it.  The relative orientation of the two points of the line probably  
affects the results, too.

Unless you want to work it out, we can add it to the bug list for  
review.

Cheers,

Don

On Sep 24, 2009, at 5:08 AM, Ruben DF wrote:

> Hi again,
>
> I was trying to solve the problem of ArcCalc. I realized when  
> ArcCalc is 180 degrees (PI radians) this turn up and down in a  
> random way when i zoom the map. I don´t know why it happens, but if  
> I create with smaller arc (176 degrees for example) this does not  
> happen. (with 177 degrees does). is it an openmap bug?
>
> Thanks in advance
> Regards
>

--
[To unsubscribe to this list send an email to "majdart@..."
with the following text in the BODY of the message "unsubscribe openmap-users"]

[Ruben DF]

Hi again,

Thanks for answering. Since it's possible there is a but with PI arcs in ArcCalc at zooming..., I thought of using OMArc class. The arc generated does not turn up and down (in a random way) like ArcCalc pressing zoom button, however, the arc has always the same shape when I'm zooming (it is not smaller or bigger according to the zoom specified).
I check generate method and I realized this method receives the projection of the figure and get the same width and  heigth of the rectangle which contains the OMArc...

Do you know what's happening? How could I get the new distance between points of arc when zoom is pressed?

Thanks in advance!
Regards


--- El vie, 25/9/09, Don Dietrick <dietrick@...> escribió:

De: Don Dietrick <dietrick@...>
Asunto: Re: [OpenMap Users] ArcCalc problem with 180 degrees arc
Para: "Ruben DF" <rdocasalf@...>
CC: openmap-users@...
Fecha: viernes, 25 septiembre, 2009 3:36

Hi Ruben,

It's probably a bug, and I say probably because you are using ArcCalc in a more vigorous way than we originally did, which was for static map images (no zooming) and for arcs less than 180.  I would guess that the trigonometry functions used in ArcCalc are giving indeterminate answers for direction when the angle is PI or close to it.  The relative orientation of the two points of the line probably affects the results, too.

Unless you want to work it out, we can add it to the bug list for review.

Cheers,

Don

On Sep 24, 2009, at 5:08 AM, Ruben DF wrote:

> Hi again,
>
> I was trying to solve the problem of ArcCalc. I realized when ArcCalc is 180 degrees (PI radians) this turn up and down in a random way when i zoom the map. I don´t know why it happens, but if I create with smaller arc (176 degrees for example) this does not happen. (with 177 degrees does). is it an openmap bug?
>
> Thanks in advance
> Regards
>