List of Math Operations

michael_mcdonald047

Is there a list of valid math expressions and operation such as cos( ), log( ), abs( ), etcetera?

abefeldman

Also check out https://cad.onshape.com/help/#numeric-fields.htm and expand the "Accepted unit keywords" field.

NeilCooke

Yes, please see the FeatureScript documentation under the help menu. 

abefeldman

Also check out https://cad.onshape.com/help/#numeric-fields.htm and expand the "Accepted unit keywords" field.

brucebartlett

check this post out too

https://forum.onshape.com/discussion/7128/a-few-expression-tips#latest

michael_mcdonald047

Thanks abefeldman, I was a little surprised to not see a div operation but see now I can just nest a '/' inside a floor() to obtain an equivalent result.  Whereas div(a,b) or (a div b) = floor(a / b).

mahir

@michael_mcdonald047, be careful. I suspect A div B = floor(A/B) only when A/B is positive. Case in point, 5 div -2 = -2, but I believe floor(5/-2) = -3. If there was a SIGN function you could use sign(A/B)*floor(abs(A/B)). But as far as I can tell, there is no sign function. You could substitute sign(X)=X/abs(X).

mahir

Or you can use an inline "if".

AdivB = (A/B>= 0) ? floor(A/B) : ceil(A/B)

Alex_Pitt

Hi, How do I square a config variable in a numeric field? (not a feature script)  I'm trying to get the hypotenuse length given #rise & #run for an array feature in a part studio. I would guess sqrt(#rise^2+#run^2) but that didn't work.  Realised I didn't know how to square a number! None of following worked: #run^2    #run*#run   #run.#run. 



Had a quick look at the Feature Script documentation but not sure which part is relevant.

Found the following but can't see a square function anywhere.

https://www.onshape.com/en/resource-center/tech-tips/tech-tip-using-numeric-fields

romeograham

You may also be running into a problem with units: your #rise variable includes mm as units. If you square that, you get mm*mm (which expresses an area, not a linear dimension). The part pattern is looking for a linear distance (only mm, not mm*mm).

You can divide by mm in your expression to cancel the units ((#rise/mm)*(#rise/mm)) which will give you a numerical value, that will get interpreted as a linear dimension (a "length") which is what the Pattern is looking for.

You could also change your Variables to be unitless - then this wouldn't be an issue.

Hope that helps!

ilya_baran

sqrt(#rise^2+#run^2) should work if #rise and #run are both lengths.  Please post a link to a version of your document where this expression isn't working and I or someone here will be able to tell you what's wrong.