HP Prime function APP  Strange limitation ! :o(  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: HP Prime function APP  Strange limitation ! :o( (/thread252120.html) 
HP Prime function APP  Strange limitation ! :o(  dg1969  10042013 Hi, In home view inside the function app I plot two functions :
F1(X): AREA(sin(X),0,X) and sincard(x) was defined with the Define shift key command as sincard(X)=sin(X)/X The plots are OK BUT inside the plot view it is impossible to use the build in "Menu>Fcn>Extremum" or "Slope".... The same occur with user function previously defined in cas world with for example f(x):=sin(x)*x What's wrong ? Thank's for your help and my apologies for my very bad english... Didier
Edited: 4 Oct 2013, 9:52 a.m.
Function ambiguity  Han  10042013 I think that the app is behaving correctly. (I don't think the HP48HP49HP50G is able to do symbolic manipulations with "program" functions either, for that matter.) Use an explicit function in F2 instead. Depending on where a "function" is created, it seems to be interpreted differently. Using DEFINE to create MYFUNC(X), MYFUNC is treated similar to regular nonCAS command, which is quite different from a function created using the CAS screen via: FUNC(X):=X^25; In this case, FUNC is considered as a function (DOM_FUNC) as well as a CAS program. One cannot use MYFUNC from the CAS to do symbolic calculations such as MYFUNC(a). (This bit is not really an issue  for me anyway  as I am sure that it is part of the "CAS vs nonCAS" design.) And all calculations with MYFUNC return nonexact values, again as if MYFUNC were a nonCAS function, as opposed to FUNC which is a CAS function. Strangely, if we define (in CAS mode): f(X):=X^25; then f is a symbolic (DOM_SYMBOLIC) and not a function. It is considered a "program" in that it returns program(X,0,X^25). However, it does not show up in the program list, and does not evaluate properly. In the CAS screen, typing f(1) produces an "Error:Invalid Input" On the other hand, symbolic functions such as FUNC (explained above) theoretically _should_ work since the calc is able to properly handle CAScreated functions. However, I am unable to get the tangent line feature to work even with CAScreated functions (perhaps again because CAScreated functions are actually still programs). Now, since f(X) (as defined above) shows up as a symbolic type, I was thinking perhaps this case should work  except it doesn't either. In fact, the plot shows up as undefined (even using CAS.f(X) in Symbolic View). Oneletter functions seem to be treated differently.
Edited: 4 Oct 2013, 11:48 a.m.
Re: Function ambiguity  dg1969  10042013 Thank's for your answer but I'am not sure to understand... I don't want to make symbolic computation I just want numerical approximation in the plot view... root, extremum or slope... For basic use with my HP50G I can define a user function with a program. For example I can create a var "MYFUNCT" that contains the following :
<< > x << x 2 ^ 2  >> >> Then I can plot MYFUNCT(X) and the build in FCN>SLOPE or EXTREMUM work just fine... I'd like to do the same with these PRIME...
Edited: 4 Oct 2013, 12:13 p.m.
