Thread: Graphs & Degrees

I'm trying to translate the slope into degrees.

I know the formula for slope (y2-y1)/(x2-x1) = slope

The difficultly is now translating that into degrees.

I saw a formula that suggested it could translate it, but in practice I've found either it doesn't or I'm using it all wrong.

(slope * 180)/(pi) = degrees

So as an example of how it's not working; slope is 40/2 = 20.

(20 * 180)/(pi) = degrees
(3600)/(3.14) = degrees
1146 = degrees

I know I've got something incorrect here, but I don't know what it is.

Any input is greatly appreciated!

Originally Posted by Phoenix999

I'm trying to translate the slope into degrees.
I know the formula for slope (y2-y1)/(x2-x1) = slope
The difficultly is now translating that into degrees.
I saw a formula that suggested it could translate it, but in practice I've found either it doesn't or I'm using it all wrong.
(slope * 180)/(pi) = degrees
So as an example of how it's not working; slope is 40/2 = 20.
(20 * 180)/(pi) = degrees
(3600)/(3.14) = degrees
1146 = degrees
I know I've got something incorrect here, but I don't know what it is.

I am sorry to tell you this, but your posting makes very little sense whatsoever.

Slope is the tangent of the angle that a line makes with the x-axis in the positive direction.
So suppose the line has slope .
If then that angle is

If then that angle is

Now in either case a mathematical cave man(i.e. someone who still uses degrees) can use that conversion formula.

Thank you for responding. I truly appreciate any help you can give. There is no reason to be sorry. If I knew what I was doing, then I wouldn't be here.

I have a photo. It is 4000 by 4000 pixels. I use a program (GIMP) to draw a random line x1 y1 to x2 y2. I am able to then ask the program for the specific x & y coordinates. I'm trying to use those coordinates to help adjust the brush's angle to match the line's (for lack of a better word) angle on the photo. I assumed using a slope equation would be the best method.

I'm hoping you could clarify some items for me.

First, I do not know what (-) stands for.
Second, can you translate arctan into caveman
And lastly, is arctan(m) = arctan * (m)

If this is the wrong area to make this post, I hope I'm not offending anyone with my simplistic inquiry. I thought this was the basic math area. If it's not, maybe someone can direct me to proper place.

Thank you and all input is appreciated.

Originally Posted by Phoenix999

Thank you for responding. I truly appreciate any help you can give. There is no reason to be sorry. If I knew what I was doing, then I wouldn't be here.

I have a photo. It is 4000 by 4000 pixels. I use a program (GIMP) to draw a random line x1 y1 to x2 y2. I am able to then ask the program for the specific x & y coordinates. I'm trying to use those coordinates to help adjust the brush's angle to match the line's (for lack of a better word) angle on the photo. I assumed using a slope equation would be the best method.

I'm hoping you could clarify some items for me.

First, I do not know what (-) stands for.
Second, can you translate arctan into caveman
And lastly, is arctan(m) = arctan * (m)

If this is the wrong area to make this post, I hope I'm not offending anyone with my simplistic inquiry. I thought this was the basic math area. If it's not, maybe someone can direct me to proper place.

Thank you and all input is appreciated.

This a mathematics help forum. As such we help people who study mathematics with their questions.
This is not a forum for those of limited knowledge.
You need to GOOGLE your question and see what comes up!

I am studying mathematics. I just have not reached this level yet. Ironically enough, I am trying to expand my knowledge. I did Google arctan and I assure you It did not produce anything that I could simply relate to your post. Try Googling (-). And the arctan(m), I'm fairly certain it is meant to be multiplied. I was simply asking for a clarification. I was polite in my first post and my second. What happened here is plainly silly.

Just as an addition, I've learned that within GIMP Script-fu, I can only use atan within my calculations. How would I convert:

If m>0 then that angle is (-) = arctan(m)

If m<0 then that angle is (-) = pi + arctan(m)

Thanks.

The answer to this thread is:

(180 * Arctan(slope) )/ Pi

or in Script-fu

(/ (* 180 (atan slope)) *pi*))

or more specifically

(set! slope (/ (- y2 y1)(- x2 x1)))
(set! angle (/ (* 180 (atan slope)) *pi*))