angle inversion problem when moved to up or down side

model · 2012-01-06 00:15:21

hy All,

I calculated angle . but when i move to up side . My angle inverted and show direction to down side .

and when i move to down side . my angle direction showed to upside . So angle is inverted .

Does any one have idea how to solve this angle inversion problem .
Thanks

Bob · 2012-01-06 00:51:45

hi model,

It sounds like a problem with the way you are calculating the angle.

In most software I would expect angles to be measured from the x axis in a counter clockwise direction (see diagram)

So to calculate that angle you would do

That would give a positive answer in RADIANS. ( x 180 / pi to get DEGREES )

Hope that helps,

Bob

model · 2012-01-06 20:16:35

hy Bob,

but i did the same .
I have current and previous position with x and y .
so just calculated deltaX = x2 - x1 and deltay = y2 - y1
double angle = arctanDegree( deltaY ,deltaX );
and i have converted it in degree, too .

Is that not same as you said ,

Bob · 2012-01-06 20:58:13

Yes it seems like it.

Carry out a 'dry run'.

On a piece of paper you put column headings for all the variables.

Then you work through your code, carefully, line by line, and enter in the columns the values for your test run.

That way you should be able to detect where the inversion occurs.

Bob

Math Is Fun Forum

#1 2012-01-06 00:15:21

angle inversion problem when moved to up or down side

#2 2012-01-06 00:51:45

Re: angle inversion problem when moved to up or down side

#3 2012-01-06 20:16:35

Re: angle inversion problem when moved to up or down side

#4 2012-01-06 20:58:13

Re: angle inversion problem when moved to up or down side

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