|Re: HP Prime - Defining a function|
Message #6 Posted by Han on 23 Oct 2013, 2:43 p.m.,
in response to message #5 by bluesun08
Many thanks for your replays. The following things are bad:
1. There is no „:=“ key similary to TI NSPIRE.
2. In CAS the function-letter will be automatically lower case (f) and in HOME screen and in APPS FUNC the function letter will be automatically upper case (F) so that i have another keystroke (Shift) for lower case (f)
3. The small x and the big X in CAS/APPS FUNC are confusing.
1. How can i reach the ' in the derivate?
2. What is the logic behind the lower case/upper case X/x F/f?
1. := can be obtained typing each character using [Alpha][-][Shift][.]
2. Single, capital letters are global, real-valued, system variables; they cannot be deleted. CAS operates with the idea that everything that is not defined is considered symbolic. And if a variable is defined, then its value will always be substituted in first. So for example, if we store 1.25 into 'x', then 1+x is interpreted as 1.25. On the other hand, if 'x' is purged, then 1+x is interpreted as a formula 1+x.
3. Yes, it is. In fact, I would go as far as saying how variables (global, local, within apps, etc) could use an overhaul.
4. [Shift][( )][Backspace] (just get double ' and delete one of them)
5. I am sure there is some "logic" but any time I make an attempt to explain (even to myself) what I think is behind upper vs lower case, I end up finding too many exceptions. I think a large number of problems that arise are the result of a design choice: merging xcas with an HP38GII. The idea itself is fine; but each of those systems has ways of handling variables, command-line input, etc. that are often conflicting at times. Over time, this should be ironed out...
Edited: 23 Oct 2013, 2:43 p.m.