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From: Berk Birand on 27 Sep 2006 23:22
Hi,

I would like to share with the good people of this forum, my very own
HP 50G story, which unfortunately is a story of disappointment.Just like
many people on this group, I recently bought my very own HP50g calculator
(my first HP, if you don't count the HP12 and HP15 emulators that I have
on my PocketPC). I received it this afternoon, and have been playing with
it since.

I was really excited about this purchase. I started reading both the
user's guide and the user's manual the minute I made the order, and I
was hoping that I could finally give my Voyage 200 to my brother. Yet
things didn't go that way, and I am currently thinking whether I did a
mistake by buying this. I am an Electrical Engineering student, and a
calculator is really dear to me. So far, my TI hasn't let me down, but I
instantly noticed the following problems with this HP.

* After using some of the equations in the library, and the finance
feature, I noticed that my home directory was swamped with variables! n,
p0, Ie0. I found this kind of frustrating, since at first I didn't know
you could select multiple files for "purging." It still seems ridiculous
to go into the file manager after using each equation and delete a bunch
of variables..

* It doesn't have that many probability mass distributions. They got
Normal, Chi-square and a few others, but what happened to the Binomial
and the Poisson? I would especially expect them to have the cumulative
distribution functions for those. Also the cdf for the Normal
distribution is 'upper-tail' so to do P(X<x), I need to perform an extra
subtraction (1-P(X>x)). What is the reason for that, I don't understand.

* Probably one of the major disappointments was this bug I found in the
equation library. When you go in one of the sections (say, Projectile
Motion), and press the PIC soft-key to look at the supposedly helpful
picture, you can't change the equation anymore! After you press EQN,
pressing the up-and-down keys scroll the screen, instead of moving
through the list of equations.

I have been reading some of the messages posted to this group, and it
seems like you grow fond to your HP with time. I hope that will be the
case for me. I still have time to return it (I think, depending on
Amazon.com's return policy). I would at least wait until I get my first
EE homework done before doing that.

I would be interested in hearing your point of view about these issues,
and how it actually compares with the Voyage 200 (you think I should give
it away?).

Cheers,
bB

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From: Patrick Legrand on 28 Sep 2006 00:09
Berk Birand schrieb:
Hi Berk

> * After using some of the equations in the library, and the finance
> feature, I noticed that my home directory was swamped with variables! n,
opposiite to the voyage200 you may nest directories. I use a TMP
directory for all temporary calculations and simply delete its content
afterwards (clvar - make sure you're in the tmp dir or it will blow away
almost everything...).
I would make sure NOT to be in the root dir when doing any calculations:
besides the automatically generated names I tend to save quite a few
intermediate results.
The feature of some automatic variables is actually pretty handy: if you
have to use a different formula on the same problem chances are high
that you need the same variables and e.g. graph settings.

> * It doesn't have that many probability mass distributions. They got
> Normal, Chi-square and a few others, but what happened to the Binomial
> and the Poisson?
many add-on progs available. check on hpcalc.org

> * Probably one of the major disappointments was this bug I found in the
> equation library. When you go in one of the sections (say, Projectile
> Motion), and press the PIC soft-key to look at the supposedly helpful
> picture, you can't change the equation anymore! After you press EQN,
> pressing the up-and-down keys scroll the screen, instead of moving
> through the list of equations.
try the softkey nxeq that appears at the same place as eqn before ;-)
cursors are for huge single formulas only

> seems like you grow fond to your HP with time. I hope that will be the
when my old 48g became too slow to solve big formulas I switched to the
Voyage200. Only to switch back to the 49G+ as it became available (I got
the unit 4 times exchanged because of breaking keys, but the last on
seems fine now). My impression is, that the voyage200 is rather a
shrinked PC (big display, easy to program - but very unhandy variable
management, only one level of sub-dirs) while HP makes calculators with
calculators in mind.
I prefer a HP (I'm used to RPN anyway) for quick (and smaller) stuff and
Maple for big projects. I gave the voyage200 to my wife and only use it
to play chess (I did not find anything close to tichess on the 50g yet)

Some quirks are left. To me the most anoying one is that the calc has to
switch to radians for the symbolic solver and does not restore the
previous setting afterwards. But this will be fixed one day (hopefully)

> I would be interested in hearing your point of view about these issues,
it takes some time to get used to. Afterwards you'll probably ask
yourselfs how you ever dealt with anything else ;-)


Good luck
Patrick
From: Jean-Yves Avenard on 28 Sep 2006 00:48
Hi
Berk Birand wrote:
> calculator is really dear to me. So far, my TI hasn't let me down, but I
> instantly noticed the following problems with this HP.

Well, all of those are rather good news anyway.
The problems you've mentioned are linked to your inexperience with HP
calculators and the fact that it's not a TI calculators.

They just work differently

> you could select multiple files for "purging." It still seems ridiculous
> to go into the file manager after using each equation and delete a bunch
> of variables..
You can create sub directories (unlike the TI) if you want to tidy up
your variables.

Actually, having variables being created is I believe one of the
strength of the HP50. You are not limited to a set of variables (e.g
from A to Z), you can create as many as you like, and store whatever you
want in them.

In EQ you will find the equation you were solving. You can recall it to
the stack (provided you're in RPN mode) simply by typing EQ or pressing
the name in the menu.
You can then evaluate the equation. As each variable of this equation
has been created in the VAR menu, you can change their value easily and
evaluate the EQ expression given the new value sotred in each variables.


>
> * It doesn't have that many probability mass distributions. They got
> Normal, Chi-square and a few others, but what happened to the Binomial
> and the Poisson? I would especially expect them to have the cumulative
> distribution functions for those. Also the cdf for the Normal
> distribution is 'upper-tail' so to do P(X<x), I need to perform an extra
> subtraction (1-P(X>x)). What is the reason for that, I don't understand.

You have many extra libraries available for the HP50G to perform very
advanced statistics. Check www.hpcalc.org and look for the Statistics
program written by Scott Guth. It will do everything you want to do and
more.


>
> * Probably one of the major disappointments was this bug I found in the
> equation library. When you go in one of the sections (say, Projectile
> Motion), and press the PIC soft-key to look at the supposedly helpful
> picture, you can't change the equation anymore! After you press EQN,
> pressing the up-and-down keys scroll the screen, instead of moving
> through the list of equations.
Press ENTER to return to the list of equations, or press EXIT (F6) in
the menu to go back to the original menu


> Amazon.com's return policy). I would at least wait until I get my first
> EE homework done before doing that.
There's quite a steep learning curve with HP calculators especially
coming from a TI background. HP calculators do work differently, it's a
different logic and they can do so much that it's hard to master all it
can do quickly.
I have no doubt that for EE the HP50 is the best machine available.
Whenever it comes to numerical evaluation, the HP is kind for its
accuracy and speed.

>
> I would be interested in hearing your point of view about these issues,
> and how it actually compares with the Voyage 200 (you think I should give
> it away?).
The Voyage 200 is a great machine, but I think it's more suited for
high-school or advanced algebra as opposed to EE work

Jean-Yves
From: Douglas Rohm on 28 Sep 2006 00:53
> * After using some of the equations in the library, and the finance
> feature, I noticed that my home directory was swamped with
> variables! n,
> p0, Ie0. I found this kind of frustrating, since at first I didn't
> know
> you could select multiple files for "purging." It still seems
> ridiculous
> to go into the file manager after using each equation and delete a
> bunch
> of variables..

Hit LS + then click on each variable to enter it into the list. Hit ENTER
to put the list on the stack. Then LS EVAL, MEM, PURGE. It will purge all
the vars in the list. You can place PURGE in your CST menu for faster access
if you want.

Doug


From: Berk Birand on 28 Sep 2006 01:25
On Thu, 28 Sep 2006 04:53:45 +0000, Douglas Rohm wrote:

>> * After using some of the equations in the library, and the finance
>> feature, I noticed that my home directory was swamped with
>> variables! n,
>> p0, Ie0. I found this kind of frustrating, since at first I didn't
>> know
>> you could select multiple files for "purging." It still seems
>> ridiculous
>> to go into the file manager after using each equation and delete a
>> bunch
>> of variables..
>
> Hit LS + then click on each variable to enter it into the list. Hit ENTER
> to put the list on the stack. Then LS EVAL, MEM, PURGE. It will purge all
> the vars in the list. You can place PURGE in your CST menu for faster access
> if you want.

Thanks for the reply, but I couldn't find the location of LS+. But it
seemed like your method of deleting variables is already longer than what
I used to do. I open the file manager, select each variable i want to
delete using ENTER, and then hit PURGE. It prompts me whether I want to
purge the variable, and I press the "ALL" soft-key to do so.

What seemed unreasonable was the actual act of picking every single
variable that the equation created manually...

Berk

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