A function in many programming languages for computing the arctangent with two arguments
A function in many programming languages for computing the arctangent with two arguments
Questions tagged [atan2]
152 questions
2
votes
1 answer
Python angle calculation for image rotation
I am working on an application which first needs to rotate an image slightly in order to deskew it.
I have detected a vertical line down the image between two points (x1, y1) and (x2,y2). The vertical line is not entirely vertical - the second x…
user1022788
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2
votes
1 answer
Signed Char ATAN2 and ATAN approximations
Basically, I've been trying to make two approximation functions. In both cases I input the "x" and the "y" components (to deal with those nasty n/0 and 0/0 conditions), and need to get a Signed Char output. In ATAN2's case, it should provide a range…
user3303504
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2
votes
1 answer
How to find clockwise angle in degree between two vector in java
First I want to call this following vector as:
Vector M1 = [O → M1];
Vector C1 = [O → E];
Vector M2 = [A → M2];
Vector C2 = [A → C];
Vector M3 = [B → M3];
Vector C3 = [B → G];
every M vector is main vector or base vector.
My problem is how to find…
Zen3515
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1 answer
Loop for atan2 function by year in R
I have an artificial data set that I created:
x<-rnorm(100,10,10)
y<-rnorm(100,20,10)
Location<-c((rep("AB", 40)),(rep("TA", 30)),(rep("OP", 30)))
Year<-c((rep("1999", 10)),(rep("2000", 9)),(rep("2001", 12)),(rep("2002", 9)),(rep("1999",…
KL2014
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2
votes
2 answers
how to redefine atan2 function from -inf to inf in matlab?
I have a rotating vector R(x(t), y(t)) and I want to find an angle as a function of time. The atan2 is determined between -pi and pi, however it is inconvenient for me to analyse all dynamics. So, is there any way to expand atan2 from -inf to inf?
anatoly
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1
vote
3 answers
Limiting atan2 to specific angle ranges
I want my Player sprite to rotate following the position of the mouse cursor.
I'm using atan2 to set up a 360 degree rotation action script for my Player sprite.
atan2(XMouse-XPlayer,YMouse-YPlayer) - 90
Using this, 90 degrees is straight up, 0 is…
user1285968
- 11
- 1
1
vote
2 answers
Weird behavior from Octave's atan2
I'm trying to port some Octave code to Java. I'm trying out atan2 so I have the following tries
octave3.2:53> m1 = [1,2;3,4]
m1 =
1 2
3 4
octave3.2:54> m2=[5,6;7,8]
m2 =
5 6
7 8
octave3.2:55> atan2(m1,m2)
ans =
0.19740 …
skytreader
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2 answers
atan2 with CGPoint Iterator
vector::iterator i;
vector* bp = bicyclePad.bikePathPoints;
for(i = bp->begin(); i != bp->end()-3; i++){
angle = atan2((*i).y/(*i).x) * 180/ PI;
}
I guess atan2 can only be used with floats and doubles. but I am trying to do…
John Riselvato
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1
vote
1 answer
VBA Atan2 function returns incorrect result
I was trying to solve a problem over on Math Stackexchange (https://math.stackexchange.com/questions/4752547/3d-transformation-matrix-to-euler-angles) and I found that my problem seems to be related to VBA's execution of the Atan2 function.
Here's a…
G.H.
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1
vote
1 answer
how to map atan2() to only positive radian?
atan2(y, x) has that discontinuity at PI (180°) where it switches to -PI..0 (-180°..0°) going clockwise.
if i apply the solution from this
// rust
(y.atan2(x).to_degrees() + 360.0) % 360.0
doesn't quite work with radians
(y.atan2(x) + PI*2.0) %…
Bob
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1
vote
2 answers
How to rotate rectangle toward mouse position on translated canvas? Javascript
——————————————————————————————
How do I rotate the gun (the gray rectangle) around the player toward the current mouse position? (preferably using vectors or Math.atan2()) Vanila Js
I have tried but it doesn't stay on the player and doesn't rotate…
Pete21
- 102
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1
vote
1 answer
How to get enemies to turn continuously using atan2()
I am trying to build a game where you control a pirate ship and other computer pirate ships try to attack you. I'm currently working on code that gets the enemies to turn to face the player, and I am running into an issue when atan2() returns a…
Alex Savic
- 11
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1
vote
1 answer
Numerical evaluation of arctangent functions
I am having difficulties to interpret results of arctangent functions. This behaviour is consistent for all implementations I came across, so I will here limit myself to NumPy and MATLAB.
The idea is to have circle of randomly placed points. The…
rad
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1
vote
1 answer
Math.Atan2(double.NegativeInfinity, double.PositiveInfinity) - bug, or undocumented breaking change?
Consider double result = Math.Atan2(double.NegativeInfinity, double.PositiveInfinity);.
In .net 4.8 this returns NaN.
In .net Core 3.1 or later this returns -0.7853981633974483.
The documentation for Math.Atan2() states:
If x or y is NaN, or if x…
Matthew Watson
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1
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2 answers
Phase angle from FFT using atan2 - weird behaviour. Phase shift offset? Unwrapping?
I'm testing and performing simple FFT's and I'm interested in phase shift.
I geneate simple array of 256 samples with sinusoid with 10 cycles.
I perform an FFT of those samples and receiving complex data (2x128).
Than I calculate magnitude of those…
Mateusz Kusmierz
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