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+--- Thread: Beginner - getting info out of function application (/thread-12881.html)
Beginner - getting info out of function application - Erik P - 04-28-2019 02:25 AM
I have been using calculators from the hp48-series for some time. I started using a hp48sx when studying engineering at university during the early 90's. However they are not sold anymore so I thought that I should enter the new era and buy my son a hp prime (of course I had to test it for myself as well).
It is very fast, however......
When I graph functions on hp50g and search for, for example, the intersection of two functions, the result is placed on the stack. If I use the numerical solver the result is placed in the solved variable. This makes it extremely easy to use the results in later calculations. Even better, if I enter a function in the solver it will be the default when graphing. (The solver was even better on hp48sx since it was very easy to enter guesses, values for variables etc.)
I can't find anything even remotely like this on hp prime. I have a hard time getting the root, intersection etc out from the function application. It seems like the fastest (only?) way to do it is writing down the results on a piece of paper and then enter the value when it is needed (not what I would call progress!).
In the solver I use copy-paste, which is not fast.
Are there any better ways?
RE: Beginner - getting info out of function application - grsbanks - 04-28-2019 10:00 AM
When all else fails, RTFM. In particular the section on the App variables that are part of the "Function" app on p127 of the latest version of the manual.
Results of analyses are stored in these App variables automatically.
RE: Beginner - getting info out of function application - lrdheat - 04-28-2019 03:02 PM
I may have misunderstood the manual (admit that it's been awhile back), but it appears as if only the last number of interest, say a root, is saved in the variables. It is not as easy to integrate in home or in the graphing app between two roots of an equation...I have wished for variables to retain last two numbers of interest...
RE: Beginner - getting info out of function application - Erik P - 04-29-2019 08:47 AM
(04-28-2019 10:00 AM)grsbanks Wrote: When all else fails, RTFM. In particular the section on the App variables that are part of the "Function" app on p127 of the latest version of the manual.
Results of analyses are stored in these App variables automatically.
I found it just hours after I posted. As important is that "user variables" are used by the "Solver" application. The result is stored in a user variable with the same name. The later is not clearly stated in the manual, at least not in the section about the "Solver" application. I can also use the functions from the "Function" application in the "Solver" application by entering Fn(X) with n = 1.. in the solver, and it is possible to use the Fn(X) functions from the "Function" app elsewhere, for example in home view.
Thus the functionality from HP50g is almost replicated, but HP Prime is a bit harder to use.
RE: Beginner - getting info out of function application - Wes Loewer - 04-29-2019 02:36 PM
When using the Function or Advanced Graphing App, the position of the cursor is stored in X and Y. So when you find a root, intersection, extreme, or whatever, you can just go to Home and put X and Y in the history so that you have access to them later. If you're going to use the value a lot, you can store it with another variable name.
I find this feature extremely useful.
RE: Beginner - getting info out of function application - lrdheat - 04-29-2019 05:16 PM
Hi Wes,
Would the saved x,y value be the value of the closest pixel to the point of interest, or the closest machine value to the point of interest?
RE: Beginner - getting info out of function application - Wes Loewer - 04-29-2019 07:44 PM
Closest machine value to the point of interest. In other words, the same value that the graphical solver finds. If you press an arrow key before going to Home, then X,Y will have the values of the cursor's pixel.
RE: Beginner - getting info out of function application - Erik P - 04-29-2019 09:30 PM
(04-29-2019 02:36 PM)Wes Loewer Wrote: When using the Function or Advanced Graphing App, the position of the cursor is stored in X and Y. So when you find a root, intersection, extreme, or whatever, you can just go to Home and put X and Y in the history so that you have access to them later. If you're going to use the value a lot, you can store it with another variable name.
I find this feature extremely useful.
Thank you! That is really a very useful feature!
Small features like this really make a huge difference when using the calculator.