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Thomas Radtke · 04-15-2015, 05:15 AM

(04-14-2015 06:57 PM)Tugdual Wrote: I wonder what 50g owners are doing with their machines for professional purposes. [...] For my day to day work, a 35S is actually the best option, not the 50G. So I would be interested in some feedback from users regarding their professional use of the calculator (anything not related to education).

(1) The G's are actually better on root solving as you may have multiple letter variables. I'm using the 35s too, but that only works since I use my formulas often and know those crippled equation representations well. I would prefer the 27S but fear it could get lost

(2) I have one 50G (not mine, our DX-engineers) calculating heat exchangers such that inlet and outlet are on one side. This usually gives a set of solutions with different specs that can be better presented on a larger display

BartDB · 04-15-2015, 12:38 PM

(04-14-2015 06:57 PM)Tugdual Wrote: I wonder what 50g owners are doing with their machines for professional purposes. I purchased one for a hobby (I never had seen RPL before) and a very few manual calculations (price calculations most of the time...) at work. When things become serious, most people would switch on Excel and myself on C++.
Anything I do on the 50g is good fun but terribly inefficient. For my day to day work, a 35S is actually the best option, not the 50G. So I would be interested in some feedback from users regarding their professional use of the calculator (anything not related to education).

I use the 50g for my normal work as I find the programmability very powerful¹. I also have a 35s and did write several of my programs for it too, but the keystroke programming is laborious. Other advantages over the 35s are:
- more powerful programming
- easier to program (you can even do it on a PC with e.g. HPUserEdit)
- save programs on SD card or PC
- when main batteries die, programs on the calculator are safe due to memory backup battery
- program checksums work, making it easier to re-enter programs if they do get deleted
- as I am used to a 28/48/50 series stack², I find it difficult to adjust to traditional stack entry with stack lift and limited to 4 levels.

Best regards.

footnotes:
1) I only use UserRPL. I have not found a need for other programming languages or SystemRPL as my programs run quick enough anyway. For anyone only requiring UserRPL, I highly recommend HPUserEdit: http://www.hpcalc.org/details.php?id=6600
2) My first HP calculator was a 28C.

Sukiari · 04-15-2015, 09:02 PM

(04-09-2015 05:50 AM)Tugdual Wrote: Glad to see another 50g thread starting here. I'm going through the same discovery steps at the moment and had many questions which I compiled in one thread to avoid flooding the forum and the community has always been very helpful.
I found your comment about stack and local variables interesting. Never thought about that before but hell you're right and I may find myself confused now .
I just started with AAA batteries and having read some other threads on this topic it seems that the 50g is indicating low battery around 4.8V which is a bit high for average 1.2V battery cells. So quite probably only very little power is consumed and quite certainly the 50g was not intended to be used with rechargeable batteries. Wonder if we can soft adjust the warning level ?

@Han
I don't think USB is charging batteries it would be dangerous with normal batteries.

I use low self-discharge type batteries in my 50g (Eneloops) and I have not had a low battery status since I put them in, in October.

Normal Ni-MH batteries lose a third of their charge per month just sitting there.

ttw · 04-16-2015, 01:56 AM

I use my HP50g for running through various mathematical computations before actually writing a program for the computer. I like to get the feel of how a computation proceeds. I also do lots of quick stuff like for investments. Sometimes just convert prices between currencies. (Don't use it much for converting units as the unit conversion stuff, IMHO, is awful. It's rather difficult to just get the conversion ration between one unit and another.)

I did figure out how to compute a running sum this week. I've been looking for a fast way for years. I'll post it as a program, but normally I just parts of the code in other programs.

<< SIZE LASTARG -> N X
<< 0 X + << + DUP >>
STREAM DROP N ->LIST >> >>

The program takes a list and outputs the sum. The 0 at the beginning is needed because STREAM needs something to work with. The DROP is because STREAM works on the hole list.

Thomas Klemm · 04-16-2015, 03:13 AM

(04-16-2015 01:56 AM)ttw Wrote: I did figure out how to compute a running sum this week.

Nice idea! You could just as well use:

Code:

\<<

  DUP SIZE \-> N

  \<<

    \<< OVER + \>>

    STREAM N \->LIST

  \>>

\>>

Cheers
Thomas

walter b · 04-16-2015, 03:57 AM

(04-16-2015 01:56 AM)ttw Wrote: The DROP is because STREAM works on the hole list.

I know hole conduction in semiconductors but didn't know a hole list so far. Learning something new here every once in a while.
(Seems to become a popular error in your language on the forum - please edit it - no personal offense intended).

d:-/

ttw · 04-16-2015, 08:37 AM

(04-16-2015 03:13 AM)Thomas Klemm Wrote:
(04-16-2015 01:56 AM)ttw Wrote: I did figure out how to compute a running sum this week.

Nice idea! You could just as well use:

Code:

\<< DUP SIZE \-> N \<< \<< OVER + \>> STREAM N \->LIST \>> \>>

Cheers
Thomas

I tested this; it still needs the prepended 0. Both programs run (for a list of size 400) in .93xx seconds (according to TEVAL.) The difference is that mine has two instances of the total as opposed to one. As that is what I need (selecting items randomly according to weights), that's what I'll use. However, when I just need the list, I'll switch to yours.

Tugdual · 04-16-2015, 09:32 AM

(04-15-2015 05:15 AM)Thomas Radtke Wrote: (1) The G's are actually better on root solving as you may have multiple letter variables. I'm using the 35s too, but that only works since I use my formulas often and know those crippled equation representations well. I would prefer the 27S but fear it could get lost

(2) I have one 50G (not mine, our DX-engineers) calculating heat exchangers such that inlet and outlet are on one side. This usually gives a set of solutions with different specs that can be better presented on a larger display

Interesting. I am on the HVAC business, wonder if we are in the same activity.
I acquired the 50g quite recently and I am not yet acquainted with it. I've seen in many occasions people (I think it was already you) mentioning that they were using the 50g for equation solving so I have been trying for some time to tame the MES which at first was really a mess.
Not sure why it looked so complicated to me but yesterday I successfully dropped all the psychometric equations into the solver and bang, now I have all air conditions with 2 input variables. Wow this is impressive, convenient and truly an engineering tool! Problem is that it becomes rapidly messy variables wise, so I created a specific directory for each set of equations. This is a bit cumbersome, wonder if there is a better way to proceed with equation sets packaging and switching.

Tugdual · 04-16-2015, 09:36 AM

(04-15-2015 09:02 PM)Sukiari Wrote:
(04-09-2015 05:50 AM)Tugdual Wrote: Glad to see another 50g thread starting here. I'm going through the same discovery steps at the moment and had many questions which I compiled in one thread to avoid flooding the forum and the community has always been very helpful.
I found your comment about stack and local variables interesting. Never thought about that before but hell you're right and I may find myself confused now .
I just started with AAA batteries and having read some other threads on this topic it seems that the 50g is indicating low battery around 4.8V which is a bit high for average 1.2V battery cells. So quite probably only very little power is consumed and quite certainly the 50g was not intended to be used with rechargeable batteries. Wonder if we can soft adjust the warning level ?

@Han
I don't think USB is charging batteries it would be dangerous with normal batteries.

I use low self-discharge type batteries in my 50g (Eneloops) and I have not had a low battery status since I put them in, in October.

Normal Ni-MH batteries lose a third of their charge per month just sitting there.

I ordered Varta batteries. They are cheaper and more common in Europe than Sanyo's Eneloops. Looking forward to see how they will perform. I also noticed that the voltage at full load is pretty high, above 1.4V but possibly the voltage decays rapidly because the nominal voltage remains 1.2V.

Tugdual · 04-16-2015, 10:05 AM

(04-16-2015 01:56 AM)ttw Wrote: I use my HP50g for running through various mathematical computations before actually writing a program for the computer. I like to get the feel of how a computation proceeds. I also do lots of quick stuff like for investments. Sometimes just convert prices between currencies. (Don't use it much for converting units as the unit conversion stuff, IMHO, is awful. It's rather difficult to just get the conversion ration between one unit and another.)

I did figure out how to compute a running sum this week. I've been looking for a fast way for years. I'll post it as a program, but normally I just parts of the code in other programs.

<< SIZE LASTARG -> N X
<< 0 X + << + DUP >>
STREAM DROP N ->LIST >> >>

The program takes a list and outputs the sum. The 0 at the beginning is needed because STREAM needs something to work with. The DROP is because STREAM works on the hole list.

How about ΣLIST ?

ttw · 04-16-2015, 12:36 PM

(04-16-2015 10:05 AM)Tugdual Wrote:
(04-16-2015 01:56 AM)ttw Wrote: I use my HP50g for running through various mathematical computations before actually writing a program for the computer. I like to get the feel of how a computation proceeds. I also do lots of quick stuff like for investments. Sometimes just convert prices between currencies. (Don't use it much for converting units as the unit conversion stuff, IMHO, is awful. It's rather difficult to just get the conversion ration between one unit and another.)

I did figure out how to compute a running sum this week. I've been looking for a fast way for years. I'll post it as a program, but normally I just parts of the code in other programs.

<< SIZE LASTARG -> N X
<< 0 X + << + DUP >>
STREAM DROP N ->LIST >> >>

The program takes a list and outputs the sum. The 0 at the beginning is needed because STREAM needs something to work with. The DROP is because STREAM works on the hole list.
How about ΣLIST ?

That gives the total. I need the running total: x1,x1+x2, x1+x2+x3....

Gilles · (This post was last modified: 04-16-2015 05:43 PM by Gilles.)

(04-16-2015 12:36 PM)ttw Wrote:
(04-16-2015 10:05 AM)Tugdual Wrote: How about ΣLIST ?
That gives the total. I need the running total: x1,x1+x2, x1+x2+x3....

[Edit]

Code:

 0 SWAP 1 << + DUP >> DOSUBS + Init

'Init' just drop last element of the list. see the powerfull and excellent GoferList Library
http://www.musikwissenschaft.uni-mainz.d...GoferLists

MarkMason · 04-16-2015, 07:47 PM

(04-14-2015 02:03 PM)rogeriol Wrote:
(04-09-2015 03:32 AM)MarkMason Wrote: [font=Arial]Received the 50g about 5 weeks ago. I bought it as a retirement toy. Had I still been a working engineer I would probably have gone with a WP-34s or 35s, but wanted
...
Mark

Funny. I got my first RPL calculator in 1990 (28S) also as a toy ......

And you got it as a retirement toy.

Yes, sounds a little funny but I found early retirement thrust upon me by a disability that requires me to be laying down 60+% of the time, outherwise I'd be out enjoying the countryside during the daytime. I hesitate to mention this, and do so only for explination, as I have many more things to be grateful for that offset this condition. Luckily I have the internet for amusement while my lady is at work all day, but there is only so many chimpanzee videos to watch on youtube. Fortunately my nurd tendencies open up whole areas of amusement, particuairly finding numbers to play with.

(04-14-2015 06:57 PM)Tugdual Wrote: I wonder what 50g owners are doing with their machines for professional purposes. I purchased one for a hobby (I never had seen RPL before) and a very few manual calculations (price calculations most of the time...) at work. When things become serious, most people would switch on Excel and myself on C++.
Anything I do on the 50g is good fun but terribly inefficient. For my day to day work, a 35S is actually the best option, not the 50G. So I would be interested in some feedback from users regarding their professional use of the calculator (anything not related to education).

Since 1989 until a couple of years ago I used a HP-32S for work, still have it, still runs good. The reason I stayed with it were basically the steeper learning curve of RPL. I learned RPN while in school and am a full convert. I vaguely remember playing with a 48 once about 20 years ago and did not have time to become familiar with it. That's the main reason that I would have probably picked a WP-34S or a 35s as a replacement had my 32S bit the dust, I could just pick them up and work immediately.

Now that I'm familiar with the 50g, it would be my work calculator should I ever be able to do that again. It's capabilities, larger screen, and logical arangement once you learn the basics of RPL are just too big of an advantage to pass up. Wish I had one in the Mojave when working there 7 years ago. With it's capabilities, and a little programming time, I would have not had to wait to get back to the office for numerical answers. In this case, having the capability would have enabled a different approach to the work in a few instances. Being in the chemical industry though would probably have killed a couple of 50g's from corrosion, but it would have been an acceptable price to pay. Oh, and the games are fun too!!!

As far as actual applications, running filtration trials there are many data points to record and flow rates are calculated by volume change over discrete time intervals. Most of the time one needs to convert a linear tank reading into the volume. All trials are timed and the 50g is very powerful for this.

For other processes, the throughput and/or efficiency is determined by a specific material balance. A little programming would have put this in my pocket for answers right in the control room. I would have liked to have a pump curve program, and still may write one just for fun if I can find some relationships to work with. Steam tables !!!! etc

Looking back, I can understand my thinking at the time. Most of the calculating was done in the office with Excel. Also, in the modern work environment, one finds oneself always on the steep part of some other learning curve constantly, usually more than one at a time. With corporate e-mail and meetings out of control and the occasional workforce reduction, there wasn't enough time to do your main job justice. But, not needing to worry about any of that now, I've had time really enjoy the 50g.

Mark

ElectroDuende · 04-17-2015, 11:46 AM

(04-14-2015 06:57 PM)Tugdual Wrote: I wonder what 50g owners are doing with their machines for professional purposes. I purchased one for a hobby (I never had seen RPL before) and a very few manual calculations (price calculations most of the time...) at work. When things become serious, most people would switch on Excel and myself on C++.
Anything I do on the 50g is good fun but terribly inefficient. For my day to day work, a 35S is actually the best option, not the 50G. So I would be interested in some feedback from users regarding their professional use of the calculator (anything not related to education).

Is the 48G use also valid for this poll? :-P

Working in meidum/high voltage, complex numers are a must. When I was at Engineering School i first used a Casio with no complex numbers support; it meant that calculation time could easily be twice as much... I tried a 32Sii for some weeks, but its complex support s far from perfect, and doing constant rec/pol conversions didn't improve speed much... so I got a 48G, and it has been my trusted tool since then. I didn't bother to test the 35S (whose complex capabilities should be closer to 48G than to 32Sii) and in case my 48 dies, I'll go, for sure, for a 50G (maybe I should get one now, just in case).

Obviously, when working on the desk, I use a computer software, but for "on the fly" calculations, the 48G sees almost daily use.

Claudio L. · 04-17-2015, 08:52 PM

(04-14-2015 06:57 PM)Tugdual Wrote: I wonder what 50g owners are doing with their machines for professional purposes. I purchased one for a hobby (I never had seen RPL before) and a very few manual calculations (price calculations most of the time...) at work. When things become serious, most people would switch on Excel and myself on C++.

I used the 50g daily for structural engineering tedious and repetitive calculations (wind pressure determination, reinforce concrete beams design, etc), plus the daily number crunching, which in this profession is quite intensive (yes, we use structural software, but the input to the programs often needs to be pre-digested, converted to local coordinates, etc.).
Switch to Excel? Only when needed to produce a printed report, otherwise I get quicker answers with the 50g. Mainly because I use an evaluation engine I wrote many years ago (for whatever reason I never got to publish it), which is great help in engineering problems in general.
Basically it gives you alternative "STO", "PURGE" and "RCL" commands, which I called XLSTO, XLPG, and XLRCL respectively (because I wrote it to provide most of the Excel funcionality for the 50g).
Basically you start a problem in an empty directory. You store numbers and formulas using XLSTO, same as you would with STO. But when you store a formula, it internally stores the formula, its result, and creates a dependency tree, so when you store a number in one of the variables, the formula is automatically evaluated and the new result stored (same as in Excel when you change the value in a cell).
For example:
4 'X' XLSTO
3 'Y' XLSTO
'X+Y' 'Z' XLSTO --> This actually stores the result 7 in variable 'Z', and internally keeps the formula for auto-recalculation.
From now on, doing for example 5 'X' XLSTO will automatically update Z with the new result. Reading the variable Z gives the numeric result only.
XLPG works as PURGE, but it removes the result, the internal formula and the references in the dependency tree.
XLRCL will return the formula associated with a name (like Z above), while a normal RCL obtains the result.
It's basically an extension where each variable in a directory may contain both a result and a formula (like a cell in a spreadsheet).

With this, I can simply provide input values and obtain results very quickly from the VAR menu. It's definitely not "terribly inefficient", quite the contrary. By the time I browse in the PC to get to open a spreadsheet, I can be reading the results on the 50g.

Voldemar · (This post was last modified: 04-22-2015 08:18 PM by Voldemar.)

Last month I got my HP 50g Blue. Yesterday on my new calculator the low battery icon begun to display. Icon is strange. Looked at, only 40 days since I start to use the calculator. Today I replaced all batteries (4 AAA batteries and backup battery). Is it normal, batteries on HP 50g last only 40 days? I use HP 50g infrequently, while learn to operate. Much more I use my good old HP 35s. I have inserted SD card in calculator. Do SD card permanently in calculator drain batteries faster? Or it does not matter? And, is it necessary to change backup battery every time the low battery icon displaed, or backup battery lasts longer than main AAA batteries? Thank You for answers.

Han · 04-22-2015, 11:01 PM

(04-22-2015 08:11 PM)Voldemar Wrote: Last month I got my HP 50g Blue. Yesterday on my new calculator the low battery icon begun to display. Icon is strange. Looked at, only 40 days since I start to use the calculator. Today I replaced all batteries (4 AAA batteries and backup battery). Is it normal, batteries on HP 50g last only 40 days? I use HP 50g infrequently, while learn to operate. Much more I use my good old HP 35s. I have inserted SD card in calculator. Do SD card permanently in calculator drain batteries faster? Or it does not matter? And, is it necessary to change backup battery every time the low battery icon displaed, or backup battery lasts longer than main AAA batteries? Thank You for answers.

Depends on how long the calculator was left on the store shelves. The HP50G is an older generation and it could be that the stock batteries have slowly drained over time. Don't forget you can always use a USB cord to power it instead of batteries.

**rprosperi** · 04-23-2015, 12:39 AM

(04-22-2015 08:11 PM)Voldemar Wrote: Do SD card permanently in calculator drain batteries faster? Or it does not matter? And, is it necessary to change backup battery every time the low battery icon displaed, or backup battery lasts longer than main AAA batteries?

I agree with Han; it is likely your original batteries are years old, which is why their life was short.

The SD card being inserted has negligible impact on battery life - however writing to the card often could make a difference, although this too is small.

The purpose of the backup battery is to keep the RAM intact when the main batteries are removed/changed. Never remove the backup battery when the main batteries are removed - you almost certainly lose all memory. However once you have installed new main batteries, it's OK to replace the backup.

Also, keep in mind that Port-2 is FLASH RAM, so you should backup your RAM to Port-2 often, both in case of battery failure, and also in case you start exploring some of the low-level and System-RPL features, which could lead to lost memory, but FLASH is not affected. There are many backup programs available at hpcalc.org.

MarkHaysHarris777 · 04-23-2015, 06:57 AM

Thanks Mark, et al, for the write-up and the tips | hints everyone.

Many vendors out there are significantly dropping prices on these units, so if you don't have one yet they are becoming more affordable lately.

I have one coming from a vendor via Amazon (in the mail). I'm pumped about it. I have had many graphing calculators but this is the first from HP. And of course, this one will be RPL ready!

A watched pot boils *very* slowly... and a watched mail box is kind'a like that !

Cheers,
marcus
Smile

Tugdual · 04-23-2015, 07:25 AM

(04-22-2015 08:11 PM)Voldemar Wrote: Last month I got my HP 50g Blue. Yesterday on my new calculator the low battery icon begun to display. Icon is strange. Looked at, only 40 days since I start to use the calculator. Today I replaced all batteries (4 AAA batteries and backup battery). Is it normal, batteries on HP 50g last only 40 days? I use HP 50g infrequently, while learn to operate. Much more I use my good old HP 35s. I have inserted SD card in calculator. Do SD card permanently in calculator drain batteries faster? Or it does not matter? And, is it necessary to change backup battery every time the low battery icon displaed, or backup battery lasts longer than main AAA batteries? Thank You for answers.

I observed the same and was shocked. I have replaced batteries by low self discharge rechargeable batteries. Next issue will be voltage. If I'm not mistaken the low battery detection is solely based on voltage and will trigger soon since rechargeable batteries are operating around 1.2V versus 1.5V for normal batteries. Therefore you may have to recharge batteries when only 33% of the available energy was drained. I wish I could have a 50g custom firmware to adjust alarm voltage to lower values more adequate for NiMh batteries.