Mathcad need denom and numer funcitons
Mathcad need denom and numer funcitons
(OP)
I am often doing control theory work where I have a transfer function in the s or z domain. There is no easy way to automatically get the numerator or denominator of the transfer function. This must be done manually which is a pain and is sometimes forgotten which create errors. There should be numer and denom functions or is there some other method of extracting the numerator or denominator? I have Mathcad 13.





RE: Mathcad need denom and numer funcitons
Peter
RE: Mathcad need denom and numer funcitons
Peter Nachtwey
RE: Mathcad need denom and numer funcitons
Try dn(x,y):=denom(y/x^2)-> and nm(x,y):=numer(y/x^2)->
(they are symbolic operators)
Stuart
RE: Mathcad need denom and numer funcitons
http://www.ptc.com/support/mathcad_relnotes.htm
Peter
RE: Mathcad need denom and numer funcitons
I will try out the numer and denom functions with polyroots tomorrow to see if I can easily generate poles and zeros. Then my pole/zero plots will update automatically too.
I wonder what other secrets there are.
My next complaint is that often Mathcad produces transfer functions where the sign is wrong for both the numerator and the denominator. Example -x/-y. Is there and easy way to make this x/y?
After that I often see functions the look like this (-b+a)/3 instead of (a-b)/3. I know this is small stuff but I would like to use my Mathcad examples in a book someday and it would be nice if I didn't have to manually edit so much.
It never hurts to ask.
Peter Nachtwey
RE: Mathcad need denom and numer funcitons
TTFN
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