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+--- Thread: How to use RPN mode with Functions? (/thread-7853.html)
How to use RPN mode with Functions? - lemontea - 03-03-2017 12:05 AM
Hello - I bought a Prime ages ago but only recently tried to use it. My 15C had been quite sufficient thus far.
Anyway I entered a function definition and then tried to resolve it at the Home screen using Textbook entry, and it was fine.
But when I switch to RPN mode I get a syntax error.
E.g., if I define F1 = X^2 (for example)
Textbook mode, I press Vars and then find the symbolic F1 entry, it shows F1 on the Home screen. Then I press the () key and then enter, say, 5. Then ENTER, and it would resolve to F(5) which is 25.
But RPN mode doesn't work. Gets error.
RE: How to use RPN mode with Functions? - Han - 03-03-2017 12:16 AM
In RPN entry, you need to place the argument(s) onto the stack. Then you would execute a command using COMMAND(n) where n is the number of arguments used by COMMAND. In this case, your command is F1. In algebraic notation, you would enter F1(5) to get 25. In RPN notation, you would place 5 onto the stack, and type F1(1).
RE: How to use RPN mode with Functions? - lemontea - 03-03-2017 12:37 AM
(03-03-2017 12:16 AM)Han Wrote: In RPN entry, you need to place the argument(s) onto the stack. Then you would execute a command using COMMAND(n) where n is the number of arguments used by COMMAND. In this case, your command is F1. In algebraic notation, you would enter F1(5) to get 25. In RPN notation, you would place 5 onto the stack, and type F1(1).
Ok thanks.
So if I define a function with X and Y, then I would enter Y and then X onto the stack, and then type F1(2) to tell it to use the last 2 entered parameters on the stack?
RE: How to use RPN mode with Functions? - Han - 03-03-2017 12:52 AM
(03-03-2017 12:37 AM)lemontea Wrote:(03-03-2017 12:16 AM)Han Wrote: In RPN entry, you need to place the argument(s) onto the stack. Then you would execute a command using COMMAND(n) where n is the number of arguments used by COMMAND. In this case, your command is F1. In algebraic notation, you would enter F1(5) to get 25. In RPN notation, you would place 5 onto the stack, and type F1(1).
Ok thanks.
So if I define a function with X and Y, then I would enter Y and then X onto the stack, and then type F1(2) to tell it to use the last 2 entered parameters on the stack?
Yes, for a general 2-variable function. Usually, F1 is intended for a single-variable function.
RE: How to use RPN mode with Functions? - lemontea - 03-03-2017 01:08 AM
(03-03-2017 12:52 AM)Han Wrote:(03-03-2017 12:37 AM)lemontea Wrote: Ok thanks.
So if I define a function with X and Y, then I would enter Y and then X onto the stack, and then type F1(2) to tell it to use the last 2 entered parameters on the stack?
Yes, for a general 2-variable function. Usually, F1 is intended for a single-variable function.
Thanks.
But I am thinking maybe I should just use Textbook mode... sad to see RPN go....
RE: How to use RPN mode with Functions? - Tim Wessman - 03-03-2017 02:20 AM
Note that specifying argument count only needs to be done when you have a variable number of arguments.
RE: How to use RPN mode with Functions? - lemontea - 03-03-2017 02:53 AM
(03-03-2017 02:20 AM)Tim Wessman Wrote: Note that specifying argument count only needs to be done when you have a variable number of arguments.
I tried not specifying anything and it didn't work.
RE: How to use RPN mode with Functions? - Tim Wessman - 03-03-2017 03:05 AM
(03-03-2017 02:53 AM)lemontea Wrote: I tried not specifying anything and it didn't work.
F1 can take a variable number of arguments.
Use the define key, define a named function, and it wouldn't require it. Nor would something like CEIL, SIN, or similar.