Scratch

soupoftomato wrote:

I wish I could understand some of that.

Me too.

Guess not.

My brain has a sad after looking at that D:

To Asia? I dunno.

I don't know trigonometry 

...but maybe scmb1 can help you

If I could read that, I might be able to answer your question. 

illusionist wrote:

If I could read that, I might be able to answer your question. 

I'll get rid of anything to do with code and just leave the equation...

x = x + cos(atan2(sy2-y1, x2-x1)*-1)*5
y = y - sin(atan2(y2-y1, x2-x1)*-1)*5

I know someone who can help you. Dines. Ask him on his project. http://scratch.mit.edu/projects/Dines/999668

Or I can just ask him in real life.

Greatdane wrote:

Basically, it depends on the context.

Usually, you would use radians to find x using cosine and y using sine, in a perfect circle. Interesting, isn't it?

However, most likely in your context is something not related to a perfect circle.

What are you trying to do with those equations?

I forget what atan is, but I know tangent is the ratio between sine and cosine, maybe that reverses it.

here's a badly made ASCII diagram (ignore the .)
.....0<---[this is the player, x1 and y1 are its coordinates)..........
..................*<[this is an enemy, x2 and y2 are it's coordinates).
........................................................................................

I am trying to find how much x and y have to change to make the enemy move towards the player. My formula worked, but I don't know WHY it worked.

TheSaint wrote:

juststickman wrote:

illusionist wrote:

If I could read that, I might be able to answer your question. 

I'll get rid of anything to do with code and just leave the equation...

x = x + cos(atan2(sy2-y1, x2-x1)*-1)*5
y = y - sin(atan2(y2-y1, x2-x1)*-1)*5

Okay, Let me explain this. 

Cosine and Sine (Cos and Sin) are used for finding ratios of angles. If you have a 45 degree angle (Pi/4 Radians), they are the same. At 90 Degrees (Pi/2), Cos is 0, and sin is one. Usually one multiplies this by how far the object moved to find out how far it moved in the X direction and in the Y direction. You formula looks like this. The inside gives you the angle that the object is moving. Cosine finds the ratio of that angle (x:y)
and then you multiply it by 5, the amount it moved.

I hope that helped.

That's about how far I could understand it 

juststickman wrote:

Comeon, where did all the people past algebra go?

I'm halfway finished with trig, but my brain still haz a sad when I look at the equation xD

juststickman wrote:

TheSaint wrote:

juststickman wrote:

I'll get rid of anything to do with code and just leave the equation...

x = x + cos(atan2(sy2-y1, x2-x1)*-1)*5
y = y - sin(atan2(y2-y1, x2-x1)*-1)*5

Okay, Let me explain this. 

Cosine and Sine (Cos and Sin) are used for finding ratios of angles. If you have a 45 degree angle (Pi/4 Radians), they are the same. At 90 Degrees (Pi/2), Cos is 0, and sin is one. Usually one multiplies this by how far the object moved to find out how far it moved in the X direction and in the Y direction. You formula looks like this. The inside gives you the angle that the object is moving. Cosine finds the ratio of that angle (x:y)
and then you multiply it by 5, the amount it moved.

I hope that helped.

Ok, that wasn't very helpful. My question was why did it work when I reversed the sin and cos.

I used sin for Y and cos for X and it worked. And no it was not 45°.

Sin is Y and Cos is X.