Learning Forum

[jonsys]

Because of parametrizing my CAD geometry in DesignModeler, I am using formulas. Under Parameters>Parameter/Dimension Assignments I want to apply this formula for one of the variables:

L and R are known and represent lengths [mm]. For sin^-1 I use the asin(arg) function. I want to get the asin(arg) value in radians but I guess something is being messed up with degrees.

That is how the expression looks like right now: @L-@R*(2*asin(@L/2/R)-1)

How should I write it?

[peteroznewman]

The output of asin is in degrees, so just divide by 57.29578 to convert to radians.

 

[Keyur Kanade]

Hi,

Arcsine, Arccosine, and Arctangent of x. x must be between -1.0 and +1.0 for ASIN and ACOS. Output is in degrees by default. Range of output is -90 to +90 for ASIN and ATAN, and 0 to 180 for ACOS. See image from help. 

Hope this helps. 

Regards,

Keyur

[jonsys]

Peter, kkanade,

thank you. now I understand that the result was in degrees. Does it allow PI constant to be used directly?

[peteroznewman]

I don't think there is a predefined variable for pi, which is why 180/pi equals 57.29578 is used above.