Sin() cos() functions acting strangely

Can’t understand this:

  • In one simple sketch sin(30) and cos(30) produce results that appear incorrect while the exact same code in another sketch (from the Examples section) returns the correct result.

  • Here’s the code in each sketch (placed in the Setup section)

  • Screenshot of the erroneous sketch + console output is attached (as a newbie I can only attach one pic). Thx for whatever insights anyone can provide!

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Hello, you need to pay attention if you are working in degrees or in radians. You can change the mode with the angleMode() function.


Hi! Default setting for both Processing and p5.js are radians. They are similar to the ° (degrees (360)) we use in Europe, however, they are between 0 and PI*2 (TWO_PI). There are several ways to make turn degrees into radians;

  • use formula: degrees*TWO_PI/360
  • use map function: map(degrees,0,360,0,TWO_PI)
  • use inbuilt functions: radians(degrees)
  • use angleMode (p5 only); angleMode(DEGREES);

I hope this helps

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Hello @psemme,

You should always refer to the references:
reference | p5.js

In this case sin() and cos() also reference angleMode() which provides a good example.


Other references:

Have fun!


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Ok - I’m embarrassed. I should have figured that out! Thx!

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Thank you! Don’t know why I didn’t remember this basic setting!

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Thank you! Appreciate the quick response.