Using LINSOLVE

Discussion:

Using LINSOLVE

(too old to reply)

2008-12-24 04:52:38 UTC

I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]
I have entered this problem 4 times checking my entry carefully but I
keep getting the error message "Invalid Dimension". I access LINSOLVE
via S. SLV. I don't understand what I am doing wrong, nor what that
error message means. I have not been able to find an explanation of
the error message Invalid Dimension in the manual so I don't know what
it is telling me. This is a very simple problem to enter and I
believe I have entered it correctly so I am completely puzzled by the
error message. I also tried to solve another simple linear system and
keep getting the same error message. What am I doing wrong? Also, is
there some place I can go to get explanations for error messages?
That subject doesn't seem to be in the manual, nor in the help system
on the calculator, nor in the book that comes with the calculator.
Thank you.

Paolo Cavallo

2008-12-24 07:03:33 UTC

Permalink

Post by JB
I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]

That should be LINSOLVE([X+Y=3 X-Y=1], [X Y]).

If I try it in ALG Mode, I get a request to switch to Approx. Only if I try it in RPN I get the expected result. That' strange...

Paolo

Veli-Pekka Nousiainen

2008-12-24 10:34:25 UTC

Permalink

on my calc (after CASCFG)
ALG
LINSOLVE([X+Y=3,X-Y=1],[X,Y])
quite correctly will return [x=2 y=1]

Post by Paolo Cavallo

Post by JB
I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]

That should be LINSOLVE([X+Y=3 X-Y=1], [X Y]).
If I try it in ALG Mode, I get a request to switch to Approx. Only if I
try it in RPN I get the expected result. That' strange...
Paolo

2008-12-24 16:17:36 UTC

Permalink

On Dec 24, 2:34 am, "Veli-Pekka Nousiainen"

Post by Veli-Pekka Nousiainen
on my calc (after CASCFG)
ALG
LINSOLVE([X+Y=3,X-Y=1],[X,Y])
quite correctly will return [x=2 y=1]
Ok, I go th rpn mode, and enter CASCFG. Then I switch to ALG. Then I enter LINSOLVE([X+Y=3,X-Y=1],[X,Y])

LINSOLVE Error: Invalid Dimension is returned. This must be a bug in
my OS. This is frustrating. Now I can't figure out how to determine
what version of the OS is on my machine. The big manual has no
listing for OS in the index.

2008-12-24 16:21:04 UTC

Permalink

I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]

That should be LINSOLVE([X+Y=3 X-Y=1], [X Y]).
If I try it in ALG Mode, I get a request to switch to Approx. Only if I try it in RPN I get the expected result. That' strange...
Paolo

I switched to RPN mode and tried to enter the problem and wasn't
successful because I got a lot of error messages Clearly I don't
know how to use RPN. Could you walk me through the RPN entry for this
problem. Please.

2008-12-24 15:10:48 UTC

Permalink

I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]

Have you ever upgraded your ROM? If not, you are probably running
2.08 which has a bug in one of the solver commands (might be MSLV
though, not be this one. . .) that stopped it from working correctly.
I'd recommend installing 2.09 available at hpcalc.org just because it
would be a good thing. :-)

believe I have entered it correctly so I am completely puzzled by the
error message.

They often are a bit cryptic unfortunately. The advanced users
reference has a big list though.

I also tried to solve another simple linear system and
keep getting the same error message. What am I doing wrong?

I'd try CASCFG first which defaults the CAS back to its desired
settings.

TW

2008-12-24 16:30:29 UTC

Permalink

I am using an HP50g, in Algebraic mode. Both the help system on the
calculator and the big manual indicate that
LINSOLVE([X+Y=3,X-Y=1],[X,Y]) will return [x=2 y=1]

believe I have entered it correctly so I am completely puzzled by the
error message.

They often are a bit cryptic unfortunately. The advanced users
reference has a big list though.

I also tried to solve another simple linear system and
keep getting the same error message. What am I doing wrong?

I'd try CASCFG first which defaults the CAS back to its desired
settings.
TW

What do I do to determine what OS I have on my machine? Also, where
do I find the advanced users
reference or is it something I buy from HP? As a beginner, there are
lots of minor things I need to learn like how do I find out what OS is
on my machine, so I think I need to wait until I advance a bit before
I try to down load 2.09 and put it on my machine. Not being able to
determine what OS I have gives me no confidence that I could
successfully down load the latest OS and successfully get it on my
machine butg I do appreciate your suggestions. Thank you.

s***@hotmail.com

2008-12-24 16:58:41 UTC

Permalink

Type VERSION to determine your OS. It will return two strings. On my
50g, it returns:

"Version HP50-C
Revision #2.09"
"Copyright HP 2006"

The "HP50-C" means it is an official HP ROM; the unofficial betas will
display "HP50-B". What is important though is the "Revision #2.09"
part. My 50g shipped with 2.08 on it, so I had to update.

I do remember reading something about 2.08 having some solver bug, so
this might be what is affecting you.

ROM 2.09 (v.92) from HP's website:

http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?lang=en&cc=us&prodNameId=3235174&prodTypeId=215348&prodSeriesId=3235173&swLang=8&taskId=135&swEnvOID=228

From hpcalc.org:

http://www.hpcalc.org/details.php?id=6484

Instructions for ROM updates:

http://www.hpcalc.org/hp49/pc/rom/

Hope that helps.

S.C.

2008-12-24 18:52:34 UTC

Permalink

Post by s***@hotmail.com

Type VERSION to determine your OS. It will return two strings. On my
"Version HP50-C
Revision #2.09"
"Copyright HP 2006"
The "HP50-C" means it is an official HP ROM; the unofficial betas will
display "HP50-B". What is important though is the "Revision #2.09"
part. My 50g shipped with 2.08 on it, so I had to update.
I do remember reading something about 2.08 having some solver bug, so
this might be what is affecting you.
http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?la...
http://www.hpcalc.org/details.php?id=6484
http://www.hpcalc.org/hp49/pc/rom/
Hope that helps.
S.C.

Thanks S. C., it helps a lot.

2008-12-24 18:56:23 UTC

Permalink

Post by s***@hotmail.com

I just checked and I have version 2.08. Perhaps that is the problem.

Veli-Pekka Nousiainen

2008-12-24 19:33:16 UTC

Permalink

That's it!!!

"JB" <***@yahoo.com> wrote
X
http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?la...

Post by s***@hotmail.com
http://www.hpcalc.org/details.php?id=6484
http://www.hpcalc.org/hp49/pc/rom/
Hope that helps.
S.C.

I just checked and I have version 2.08. Perhaps that is the problem.

2008-12-24 20:07:55 UTC

Permalink

On Dec 24, 11:33 am, "Veli-Pekka Nousiainen"

Post by Veli-Pekka Nousiainen
That's it!!!

Just to make sure that I understand, When you say "That's it!!!" are
you refering to my OS version? That the problem is a bug in version
2.08 that is corrected by version 2.09? I wonder if I can send my 50g
to Hp and have them update the OS? I looked at the update
instructions and just don't understand the terminology and would
probably mess up my calculator if I try to do it myself. Oh well,
thanks everyone for the help. I sincerely appreciate it. Merry
Christmas.

s***@hotmail.com

2008-12-24 21:43:34 UTC

Permalink

Post by JB

Post by Veli-Pekka Nousiainen
That's it!!!

I don't think HP will update ROMs. Do you have an SD card? If so,
maybe this video walkthrough will help:

http://video.google.com/videoplay?docid=4782813003899849336&ei=yqpSSeSALYH6qgK4xfjvCw

If not, there is a second way to update the ROM. This uses the PC
connectivity kit (I don't think Macs are officially supported by HP at
the moment, but there is an app on SourceForge) called Conn4x:

http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?lang=en&cc=us&prodNameId=3235174&prodTypeId=215348&prodSeriesId=3235173&swLang=8&taskId=135&swEnvOID=228

Instructions for the ROM update using Conn4x:

http://www.educalc.net/2137081.page

Instructions for the ROM update using an SD card (in slightly
different wording than on hpcalc.org):

http://www.educalc.net/284489.page

S.C.

Veli-Pekka Nousiainen

2008-12-24 21:58:33 UTC

Permalink

On Dec 24, 11:33 am, "Veli-Pekka

Post by Veli-Pekka Nousiainen
That's it!!!

You are so right, sir!

John H Meyers

2008-12-24 23:17:21 UTC

Permalink

Post by TW
I'd try CASCFG first
which defaults the CAS back to its desired settings.

Yes, LINSOLVE works if CASCFG is performed first.

The fact that one may otherwise get an internal error,
rather than a request to change some mode or setting,
if every flag is not already pre-set to a particular state,
is more or less a bug, for which CASCFG is the work-around.

ROM 2.09 is pretty good, and 2.10 (wherever it is)
is no doubt slightly better, and I wonder, upon which version
are any plans for an "HPGCC rom" going to be based?

[r->] [OFF]

John H Meyers

2008-12-25 01:01:10 UTC

Permalink

Besides LINSOLVE erroring,
another example where things go a bit wild
if CASCFG is not performed first, viz:

a REF command may perform RREF instead,
or may also give "Undefined Local Name"
for those commands and others:
http://groups.google.com/group/comp.sys.hp48/browse_thread/thread/40257c7862d9bfe7

Here's a case needing "Rigorous" mode,
which is included in what CASCFG sets up:
http://groups.google.com/group/comp.sys.hp48/msg/eb33ed54167bf041

The precise actions of CASCFG and XQ:

The CASCFG command sets all the CAS' favorite modes in advance
(clears flags -2, -3, -99 thru -116, -118 thru -127,
sets flags -17 [RADian angles], -27, and -128),
in addition to resetting some items found in CASDIR
(VX, EPS, PERIOD, REALASSUME, MODULO).

The XQ command clears flags -2, -102, and -105 (producing Exact mode),
and converts all reals in expressions to integers or fractions,
without otherwise mucking around with other mode settings,
so it can be useful in preparing any input containing "reals"
to be acceptable to the CAS, but with fewer side-effects.

Other details at
http://groups.google.com/group/comp.sys.hp48/msg/54c3334013daea75

An old post with details about CASDIR, CASCFG, STOVX, RCLVX:
http://groups.google.com/group/comp.sys.hp48/msg/fd073474e53d846b

Note:

STOVX and RCLVX were subsequently added to the UserRPL command set,
so there is now no need to create programs for them.

[r->] [OFF]