topic Re: How to use maths functions with my parameters, eg asin(d1/d3) in Fusion Support Forum

How to use maths functions with my parameters, eg asin(d1/d3)

simon.dyer — Wed, 24 Jan 2024 00:42:14 GMT

How can I pass my parameters into maths functions ?
Eg to get the angle from my parameter using this formula,
asin(MyParameterValue)
cannot be evaluated.
I have tried all methods I can find and now asking here.
Please see below images.

Re: How to use maths functions with my parameters, eg asin(d1/d3)

admin43NL6 — Mon, 29 Jan 2024 19:51:04 GMT

If the units of the AdjOverHyp are set to "No Units", I am able to evaluate this expression in my copy of Fusion (see attached screenshot). If the units are set to mm, it doesn't work (you can only take the arcsin of a unitless number). I don't know why nothing is listed in the "Units" column of AdjOverHyp, but the dialog box in the second screenshot seems to indicate that the units are in fact "mm".

I don't believe that it's possible to change the dimension of a parameter after initial creation. It is possible to change mm to cm because they are both lengths, but it is not possible to change mm to unitless, so I think you will have to delete AdjOverHyp, recreate it as a "No Units" parameter and then try again.

Re: How to use maths functions with my parameters, eg asin(d1/d3)

jhackney1972 — Mon, 29 Jan 2024 20:38:49 GMT

If you want to easily change the Length units of mm to No Units by simply dividing the length units by 1mm as shown in the screen capture. This is common mathematical process used to cancelling out units.

Re: How to use maths functions with my parameters, eg asin(d1/d3)

admin43NL6 — Tue, 30 Jan 2024 05:25:56 GMT

Sure, that allows the function to compute, but the more fundamental issue is that AdjOverHyp should be defined without units, assuming that it represents a length, Adj, divided by another length, Hyp. If the parameters are defined with the wrong units, problems similar to this can crop up later in the design process.

If you have a parameter, Adj, which equals 0.1 mm and you want to evaluate the trig function using a hypotenuse length of 1mm, then what you propose is reasonable.

It is unclear to me why the unit column in the PARAMETERS table of the OP is blank for the entry AdjOverHyp.