newbie impressions

[gteague]

first, let me hasten to add i'm an hp prime newbie, but not a newbie to electronic gadgets and software. i actually got this calculator about 6 months ago when amazon promoted it, but other than briefly testing it i've gone on to other projects (such as building my small collection of other cp calcs back up as i lost all mine in a recent move) and just pulled it out again yesterday when i was trying to decide whether i needed an hp-48gx or maybe even a <gasp> ti-inspire cas.

so what is the thinking on having it automatically power up when you plug it into power? if i want to charge it, i hardly want a huge, color, backlit display sucking out my current. also, as i posted in another thread which everyone seems to have abandoned, it charged just fine yesterday in about 2.5 hours at around 600mah and the battery is 1500mah, so that's nearly exactly the correct amount of time.

but, with hardly any use after a full charge, it suddenly alerted saying the battery was critically low and and the green light started blinking. i asked questions about exam mode in the other thread with no response. so today i put it back on the charger and now it's not acting right. it's pulling too much current (660mah) for too long (over 3 hours now). i did discover the damm thing had turned on under the cover and hopefully that's why it's taking so long.

so while it was charging i decided to try the hp-connect software. i despise windows, but since there's no mac support i know i'll have to use it to update the firmware since hp didn't put in an sd card slot. most cameras update their firmware by simply putting the file on this card and having the camera read it and that would have been my choice for calculators as well so everyone, no matter their os, could updated their calculator.

when i turned on the calculator, _another_ hp-prime showed up in the left-hand panel. this could not be more confusing. which one do i use? why are there two? and it's not like it acts consistently either--sometimes if you turn off the calc, one will go away and then sometimes it comes back.

it's not at all clear that if you use the calculator while it's connected whether it's interacting with the app or not. there's /messages/ and /monitor/ panels and unless those are for group and classroom use, i have no idea how they're interacting with each other. and one or the other seems to be connected to the hp prime emulator app supplied with the connectivity pack, but not to the actual calculator.

<sigh> i guess i'm in for 8 hours of reading docs. at my age i hate to put that much time into learning something i'm not even sure i want to use yet. but there's so many gotacha issues the newbie is going to run afoul of that you can't just forge ahead and learn as you go it seems.

anyway, if anyone has tips on what to read first, it might save me some time. i have a whole folder full of dozens of docs and tutorials. i'm starting with the quick start guide in the meantime.

/guy

[gteague]

nevermind. it's not just me. most of what i complained about seem to be program bugs pure and simple. i'll just have to continue to not use this app unless it's a firmware update.

so i found in the settings some settings for exam mode. i set the timeout to 15 minutes, the password to 'EXIT', and set the led to blink. but this isn't going to stick if i do a reset, right? and it only goes into exam mode when i do a reset, right?. it sounds like a serious catch-22 to me. [g] and why would hp go to all the trouble to set it up so the student had no control over the mode and then let him or her set their own password? this stuff is not adding up so far. and i'm not amused to spend hours of my time defeating the kiddy parental control features instead of exploring the calculator.

/guy

[DrD]

Patience, my friend. You just need to dive in and make some mistakes. It's all about experience, and that takes awhile to absorb. Many have gone before you, and some of us still linger on ...

I've had plenty of calcs. Hp and otherwise. I like the prime. It's been relatively easy for me to get it doing what I've wanted it to do.

-Dale-

[gteague]

tks drd. i made it all the way through the quick start guide, but i don't know enough mathematics to use most of the last half of this guide and i mostly skipped it.

one thing that frustrates me is that they've made most things more complicated rather than simplified. maybe it's for progress elsewhere but i resent having to learn stuff all over again that i once knew.

for example, the first hp calc i owned which did what we call 'cas' today and i used to call 'symbolic algebra', was the 28s, so that's where i learned what little i know. for just the simplest example, if you entered the equation: 'i=e/r' in one line and then 'r' on the next line and selected 'isol' (for isolate) from the /algebra/ menu and hit /enter/ you'd get the re-arranged equation with 'r' on the left side.

but it seems they're deprecated this very logical and self-explanatory structure for the solve() command and you have to figure out for yourself that if you include a comma and an 'r' at the end of the equation, it does an isolate. i salute the more compact factor which only uses one line, but they don't bother to explain this trick. and i'm not a mathematica or maple user, from which this structure seems to be copied.

(btw, i found a used 28s on ebay last week and pounced on it. but all of those old 20-40 year old hp's i used to own have horrible displays and iphones and ipads have spoiled me. i also loved the way the 28s used rpn natively, but all you had to do was hit a leading ' and it would parse your input algebraically.)

my goal is to learn enough to be able to write a program that would take an equation and break out every variable possible and show the equation with each variable isolated on one side. i realize this is elementary algebra, but it's a tool that would be very useful to me considering how error-prone i am trying to do this manually while going through text and reference books and working the examples.

/guy

[cyrille de brébisson]

Hello,

Look at the lname function (lists all the variables used in an equation) and of course solve...
'all you need to do' is a for loop on the result of lname with a call to solve for each item in the lname list.


And yes, Prime is no 28, it is an algebraic machine, not a RPN one and as a result, things are different.
You will find that Prime is insanely powerful!

Cyrille

[Aries]

Solve({x^2+2*x+1>0,x^2-8*x<=0})



Empty set ?????

Solve({logb2(2*x+17)-logb2(x+10)=logb2(-x-4)-3})



Is x=-22 part of the domain ?

Solve({logb2(x+5)=logb4(x+7)



The Prime does not seem to be able to change the base on its own.
Very powerful, without a doubt !
Best,

Aries ;-)

[Tim Wessman]

You running a very out of date version?

(03-21-2016 04:21 PM)Aries Wrote:  Solve({x^2+2*x+1>0,x^2-8*x<=0})

Works fine...

http://www.wolframalpha.com/input/?i=sol...89%A40}%29

Quote:Solve({logb2(2*x+17)-logb2(x+10)=logb2(-x-4)-3})

[...]

Is x=-22 part of the domain ?

Yes. Unless restricted to real.

http://www.wolframalpha.com/input/?i=sol...4%29-3}%29

Quote:Solve({logb2(x+5)=logb4(x+7) [...] The Prime does not seem to be able to change the base on its own.

Yup, you can still get the result though. Maybe the author of the CAS will chime in as to why the exact solve does not work.

You are going to find much more capability and advanced features in the prime CAS that can't be done on any other "calculator" then you will find things the prime CAS doesn't handle.

Note that I am not saying it is perfect. In fact, I think its biggest weakness is that the effort has not been in making "simple" things work well and returning "nice" results and hence it tends to fail in some simple things other cas systems have no issue with. The author has an assumption of users being able to do things and recognize different forms of answers that is probably much higher then a lot of other more basic CAS systems.

[Fortin]

The log base problem works fine with solve if first put in the following format: logb - logb = 0, then simplified.

[gteague]

(03-21-2016 05:46 AM)cyrille de brébisson Wrote:  Hello,

Look at the lname function (lists all the variables used in an equation) and of course solve...
'all you need to do' is a for loop on the result of lname with a call to solve for each item in the lname list.


And yes, Prime is no 28, it is an algebraic machine, not a RPN one and as a result, things are different.
You will find that Prime is insanely powerful!

Cyrille

thanks cyrille! i'm only a program dabbler, but that sounds like something i could tackle. at least it's a goal i can set myself to try for.

and i like you putting the 'all you need to do' in quotes. long ago i worked with a small team of computer admins and when i came on for the night shift we'd have a meeting and if they had left me something particularly difficult to sort out, that was the preface to them giving me the bad news: 'now, all you have to do is ....', and when i heard that i knew there would be no napping on the job that night!

/guy

[Aries]

(03-21-2016 05:08 PM)Tim Wessman Wrote:  You running a very out of date version?

(03-21-2016 04:21 PM)Aries Wrote:  Solve({x^2+2*x+1>0,x^2-8*x<=0})

Works fine...

http://www.wolframalpha.com/input/?i=sol...89%A40}%29

Quote:Solve({logb2(2*x+17)-logb2(x+10)=logb2(-x-4)-3})

[...]

Is x=-22 part of the domain ?

Yes. Unless restricted to real.

http://www.wolframalpha.com/input/?i=sol...4%29-3}%29

Quote:Solve({logb2(x+5)=logb4(x+7) [...] The Prime does not seem to be able to change the base on its own.

Yup, you can still get the result though. Maybe the author of the CAS will chime in as to why the exact solve does not work.

You are going to find much more capability and advanced features in the prime CAS that can't be done on any other "calculator" then you will find things the prime CAS doesn't handle.

Note that I am not saying it is perfect. In fact, I think its biggest weakness is that the effort has not been in making "simple" things work well and returning "nice" results and hence it tends to fail in some simple things other cas systems have no issue with. The author has an assumption of users being able to do things and recognize different forms of answers that is probably much higher then a lot of other more basic CAS systems.

Thanks, Tim, all is working fine now, thank you !



Solve({logb2(2*x+17)-logb2(x+10)=logb2(-x-4)-3})
"Complex" is off ("i" is also off) in the CAS settings.

About the result ([-22,-8]), I'm wondering why some of the algebric expressions are solved in the C domain while others in the R domain (or in a "mixed" mode).
Is there a way to unambiguously "discriminate" the two ?
Best,

Aries ;-)

[Aries]

(03-21-2016 05:17 PM)Fortin Wrote:  The log base problem works fine with solve if first put in the following format: logb - logb = 0, then simplified.

Thank you, Fortin, does work fine, thanks for the tip ;-)
Solve(simplify(logb2(x+5)-logb4(x+7)=0)) gives the right result: [-3].
Best,

Aries :-)