What you want to use is often called the “perp dot product”, that is, find the vector perpendicular to one of the vectors, and then find the dot product with the other vector. if(a.x*b.y – a.y*b.x < 0) angle = -angle; You can also do this: angle = atan2( a.x*b.y – a.y*b.x, a.x*b.x + a.y*b.y … Read more
math.atan(x) returned in radian, if you want degree, convert it using math.degrees(x) Converts angle x from radians to degrees. >>> import math >>> math.degrees(math.atan(1.18)) 49.720136931043555
One informal but rather intuitive way to think about this is to consider the 2 components of a vector: direction and magnitude. Direction is the “preference”https://stackoverflow.com/”style”https://stackoverflow.com/”sentiment”https://stackoverflow.com/”latent variable” of the vector, while the magnitude is how strong it is towards that direction. When classifying documents we’d like to categorize them by their overall sentiment, so we … Read more
Math.cos() expects the parameter to be in radians. This will return the result you need: Math.cos(Math.toRadians(50));
I wrote an article about finding the bounding coordinates: http://JanMatuschek.de/LatitudeLongitudeBoundingCoordinates The article explains the formulae and also provides a Java implementation. (It also shows why IronMan’s formula for the min/max longitude is inaccurate.)
If you get deltaX and deltaY from your coordinates then Math.atan2 returns the arctangent of the quotient of its arguments. The return value is in radians. var deltaX = x2 – x1; var deltaY = y2 – y1; var rad = Math.atan2(deltaY, deltaX); // In radians Then you can convert it to degrees as easy … Read more
function rotate(cx, cy, x, y, angle) { var radians = (Math.PI / 180) * angle, cos = Math.cos(radians), sin = Math.sin(radians), nx = (cos * (x – cx)) + (sin * (y – cy)) + cx, ny = (cos * (y – cy)) – (sin * (x – cx)) + cy; return [nx, ny]; } … Read more
Just get a random angle: var angle = Math.random()*Math.PI*2; Then x = Math.cos(angle)*radius; y = Math.sin(angle)*radius; Done.
We have the acos function, which returns the angle in radians. >>> import math >>> math.acos(0) 1.5707963267948966 >>> _ * 2 – math.pi 0.0
Rotating a vector 90 degrees is particularily simple. (x, y) rotated 90 degrees around (0, 0) is (-y, x). If you want to rotate clockwise, you simply do it the other way around, getting (y, -x).