HP 50G help

[Sukiari]

(04-24-2015 11:52 AM)Tugdual Wrote:  

(04-24-2015 11:08 AM)Marcus von Cube Wrote:  As far as I know the 50g looks in all directories up the directory tree, at least in the home directory.

Now that is something absolutely fundamental I didn't know.
Thanks Marcus.

Yeah it really should drive home the point that you are to do very little in the HOME directory. First thing I did when getting my 50G (and 48G) was to create a temp directory so I didn't end up with things in HOME cluttering up other operations.

Every project gets its own directory, except when it depends on another project - then it gets a subdirectory under that project. This should be a rule!

[Gilles]

(04-25-2015 02:23 PM)Marcio Wrote:  

(04-25-2015 12:48 PM)Gilles Wrote:  The precision (and the time to solve !) of the numeric solver depands on "Number format" (MODE FIX 4 for example for a precision of 4 digits)

Are you sure of your equation (the 1/a part) ?

If your equation is OK, the numerical solver returns results with a guess <> 0 (because of 1/a ?) : a=1.3447... a=2.2067... etc.

EDIT : same problem with guess = 0 on the Prime... and same results...

What function are you calling to find the roots on the Prime? If you're calling solve, fsolve or nSolve from HOME you might get "unpleasantly surprised". Have a look at this thread.
The Solve app will work as expected though.

I used the APPS Solve. (Don't work with guess 0 => On )

[Sukiari]

(04-24-2015 05:19 PM)Tugdual Wrote:  

(04-24-2015 04:23 PM)DavidM Wrote:  From the AUG (Advanced Users Guide) for the RCL command:

Though it's not stated explicitly, this same behavior is applied to many built-in operations where an implicit RCL of a variable is executed. I can't remember the details at the moment, but I'm pretty sure there are at least a couple exceptions to this rule. It all boils down to which SysRPL opcode is used to get a variable's contents onto the stack. Most of the time the parent directories are searched.

Note that this isn't the same as searching all directories. Just the ones in the current path are included.

It is indeed something fundamental to understand.
But this being said is that the right way to go? The calculator would naturally feed the root directory with a lot of crap and a purge is tedious; my conception of a directory is precisely to isolate/encapsulate problems in their own context. So when I create a subdir I would expect to start with a blank page.
In my humble opinion, this mechanism totally ruin the concept of directories.

It is easily dealt with by creating a temp directory and doing your manual calculations and scratch work in there. When you have a stroke of genius simply move your program to a new directory. When the scratch directory gets too cluttered just delete and create it anew.

You don't download files and save your work to your computer's root directory, do you? While a computer does not inherit everything in its parent directories like the 50G it is just as poor in form. I guess the difference makes sense if you think of the 50G as being different from a computer - it is a customizable math environment.

[Marcio]

(04-25-2015 02:38 PM)Gilles Wrote:  I used the APPS Solve. (Don't work with guess 0 => On )

The solver on the 50g is a bit "outdated" and can't handle singulaties that well.

[Sukiari]

(04-25-2015 02:46 PM)Marcio Wrote:  

(04-25-2015 02:38 PM)Gilles Wrote:  I used the APPS Solve. (Don't work with guess 0 => On )

The solver on the 50g is a bit "outdated" and can't handle singulaties that well.

On the other hand it's a fully integrated and relatively bug-free feature, on a real RPN / RPL calculator that doesn't crash all the time.

[Marcio]

(04-27-2015 10:05 PM)Sukiari Wrote:  On the other hand it's a fully integrated and relatively bug-free feature, on a real RPN / RPL calculator that doesn't crash all the time.

I wouldn't call that a bug but I see your point.
Actually, I have never seen a bug on the 50g so far.

[Hlib]

I need the help to calculate definite/indefinite triple integrals in RPN mode on HP-50G. UG and AUR can't give advice. I usually calculate them on FX-2.0 as I can't understand HP's logic here.
SSS###dxdydz. Also, n-th derivative
EDIT: solved.

[Hlib]

From HP50g / 49g+ / 48gII graphing calculator
advanced user’s reference manual, chapter "RPL Programming 1-44,45":

Example: The following program executes INPUT to prompt for a social security number, then extracts two
strings: the first three digits and last four digits.

<<
"Key in S.S. #"
{ " - - " -1 }

INPUT
DUP 1 3 SUB
SWAP
8 11 SUB

>>

Calculator returns
[ INPUT Error:
Bad Argument
Type ]

I tried to edit many times, only to plunge more deeply into the mire of HP's manuals. So, can any one to help me in this case?

[DavidM]

(07-23-2015 04:26 PM)Hlib Wrote:  From HP50g / 49g+ / 48gII graphing calculator
advanced user’s reference manual, chapter "RPL Programming 1-44,45":

...

{ " - - " -1 }

...

I tried to edit many times, only to to plunge more deeply into the mire of HP's manuals. So, can any one to help me in this case?

Are you certain you've typed in the program exactly as it is given in the reference manual? I've tested this on a 50g with approximate mode both on and off, and in each case the program gave the expected results.

Note that the string in the list should actually have more spaces than is shown in your post, but that may simply be a result of the natural consolidation of spaces in HTML. If you look carefully in the manual you'll notice that there are 3 spaces, then a dash, 2 spaces, another dash, and then 4 spaces. This is important for the code to work properly, since it assumes a string in the "999-99-9999" format for this example to produce the expected results. Even without the extra spaces, though, the code should return something instead of producing the error you're seeing.

[Hlib]

Thanks for an answer, DavidM. I twice checked for my post in "preview" before "Post Replay". Amased with missing of my "spaces", but it doesn't matter because I did it all exactly as in reference. HP-48gii gives as it is, ("Version HP49-C
Revision #1.23"
"Copyright HP 2003")
HP-50G gives "Invalid Syntax" in the same case ( "Version HP50-C Revision #2.15" etc.). Google was not help in details. I can do without these bugs in calcs, but it would be desirable to know.
When I worked with different models of CASIO , I had no neither computer nor Internet in that past remote, but could even write aditions to their guides with tips and tricks without any forums.
I started becoming stupid with HP :-( .

[rprosperi]

(07-23-2015 04:26 PM)Hlib Wrote:  From HP50g / 49g+ / 48gII graphing calculator
advanced user’s reference manual, chapter "RPL Programming 1-44,45":

Example: The following program executes INPUT to prompt for a social security number, then extracts two
strings: the first three digits and last four digits.

<<
"Key in S.S. #"
{ " - - " -1 }

INPUT
DUP 1 3 SUB
SWAP
8 11 SUB

>>

Calculator returns
[ INPUT Error:
Bad Argument
Type ]

I tried to edit many times, only to to plunge more deeply into the mire of HP's manuals. So, can any one to help me in this case?

Is there a space between the "-" and the "1" in the 3rd line? This is the difference between the 2 state ments minus and one vs. the single statement "-1". Probably the culprit...

[Hlib]

(07-23-2015 09:32 PM)rprosperi Wrote:  Is there a space between the "-" and the "1" in the 3rd line? This is the difference between the 2 state ments minus and one vs. the single statement "-1". Probably the culprit...

Yes, there is a space. I studied manuals very carefully and I couldn't be mistaken in this simple example . I also didn't miss any '¬' there where it is necessary. Now to me laziness to check all this by the 101st time to tell - doesn't work. How it can be: almost all examples work except the mentioned? I will try further ...

[Brad Barton]

(07-23-2015 10:18 PM)Hlib Wrote:  

(07-23-2015 09:32 PM)rprosperi Wrote:  Is there a space between the "-" and the "1" in the 3rd line? This is the difference between the 2 state ments minus and one vs. the single statement "-1". Probably the culprit...

Yes, there is a space. I studied manuals very carefully and I couldn't be mistaken in this simple example . I also didn't miss any '¬' there where it is necessary. Now to me laziness to check all this by the 101st time to tell - doesn't work. How it can be: almost all examples work except the mentioned? I will try further ...

This program works fine on my 50g. I did make a couple of mistakes when I initially entered the program.

1) I forgot to turn of the alpha lock after I was done with the input statement. This caused my 2nd set of double quotes to only show one double quote, instead of a pair. Since the double quotes are a reserved expression, I doubt that a alpha-generated double quote is interpreted the same as a pair of them generated from the normal program entry mode.

2) I had to eliminate the space between the negative sign and the 1 in the input format statement.

Once I corrected those problems the program ran correctly. I didn't include any '¬' symbols.

I'm not sure if you're making the same mistakes as I did, but I thought I'd provide another data point.

Brad

[rprosperi]

(07-23-2015 10:18 PM)Hlib Wrote:  

(07-23-2015 09:32 PM)rprosperi Wrote:  Is there a space between the "-" and the "1" in the 3rd line? This is the difference between the 2 state ments minus and one vs. the single statement "-1". Probably the culprit...

Yes, there is a space. I studied manuals very carefully and I couldn't be mistaken in this simple example . I also didn't miss any '¬' there where it is necessary. Now to me laziness to check all this by the 101st time to tell - doesn't work. How it can be: almost all examples work except the mentioned? I will try further ...

Sorry, my comment may have been unclear - there should NOT be any spaces between the minus and the one, e.g. "-1" is correct, "- 1" is NOT correct. If you change that, it will probably work. The extra space is entered when you type the minus char and then the 1. Instead, if you type 1 then [+/-], it will be entered properly.

[Hlib]

Thanks to all! It was especially important for me to know that a problem exactly for my part (Post: #28) and if it works at somebody's calc.
The problem is solved. I corrected a typo, and this example well works at HP-50g now. But... 48gii still was printing an error. I checked and compared all flags on both calculators, and eventually transferred the file from 50g to 48gii through IrDA port. Now everything became clear: bug is in 48gii, as after that he still didn't want to carry out this code.

[Hlib]

Anybody, please, describe to me properties of a port 0:IREM. What does it necessary for? My experience doesn't coincide with the description in AUR and UG (HP-50G). It is like hidden-reserved scope.

[Claudio L.]

(08-14-2015 04:25 PM)Hlib Wrote:  Anybody, please, describe to me properties of a port 0:IREM. What does it necessary for? My experience doesn't coincide with the description in AUR and UG (HP-50G). It is like hidden-reserved scope.

The "Ports" are areas of memory for storage, typically used for data that is not modified often.
To fully understand "why" there's port memory when you could perfectly well store things in variables you need to look back in time. Back in the day you had a small amount of ram, and you could buy memory cards to "expand" your memory.
Originally, the numbered Ports were those additional RAM modules you could install in an external RAM card. Some cards would allow to "merge" part of that extra RAM into your main memory, and the rest was in "Ports".
Access to those ports was in "banks", so not all memory was visible at all times, you had to switch banks to access the different ports.

Now as far as Port 0: it's in main RAM, takes your user space, and is not banked, so it's actually none of the above. But it retains that special way to access it, separate from the rest of the memory.
Port 0 actually grows and shrinks as you store objects, so it's slow to store objects (it's much faster to store them in variables). However, because it's not banked, reading from it is very fast, unlike for instance Port2, which is banked and it's Flash, not RAM.
I personally have never, ever used Port0 for anything, as it consumes main RAM permanently. On the 50G you have Port1 (ERAM) for that, which is banked (hence a bit slower access) but doesn't consume main memory. And for more permanent libraries, port 2 (Flash).
There's, however, some old libraries that may need to run from Port0 because they are incompatible with banking. They are very rare but you may find some in hpcalc.org (the installation instructions would tell you if you must install in Port0).
That's the only "modern" use I can think of for Port 0.

[Hlib]

Claudio, thank you for your detailed answer. Now a new question arose: where can I find information (not UG/AUR) about User/System flags? I think I was not able to fully understand. I would be grateful for a fundamental explanation.

[ttw]

One idea that sometimes helps in doing symbolic manipulations is to replace named constants like "a" in the OP with a big prime like 997. Then, even if the symbolic program doesn't work well with letters, the traces of 997 (or whatever) can be used to unravel the answer. One tends to get things like (a-1) or a**2 or the like.

Really big primes are needed so that simple operations like differentiation or integration will not create the numbers; clearly small numbers like 2,3,4,... can be generated algebraically. Numbers like 997 are rarer. If 997 seems to small, 1000033 may be used.

[Hlib]

Can anybody explain me distinctions in use of system and user flags? I would like to get an example in the style like "1 minmarv".