MES on Prime?

[Tugdual]

I used to have a Prime and moved on the 50g. I recently discovered the MES, Multiple Equation Solver, which I found quite impressive a tool. I don't remember having seen anything equivalent on the Prime, did I miss something?

[Han]

(04-17-2015 05:56 PM)Tugdual Wrote:  I used to have a Prime and moved on the 50g. I recently discovered the MES, Multiple Equation Solver, which I found quite impressive a tool. I don't remember having seen anything equivalent on the Prime, did I miss something?

Try the solver app... ?

[Marcio]

(04-17-2015 06:01 PM)Han Wrote:  

(04-17-2015 05:56 PM)Tugdual Wrote:  I used to have a Prime and moved on the 50g. I recently discovered the MES, Multiple Equation Solver, which I found quite impressive a tool. I don't remember having seen anything equivalent on the Prime, did I miss something?

Try the solver app... ?

which is a lot faster and can take a lot more equations than MES.

[Tugdual]

(04-17-2015 06:01 PM)Han Wrote:  Try the solver app... ?

I did, and just had a very hard time. Here are the issues I found:
1. you need to create all variables having a name other than A..Z manually using STO in home prior to entering equations otherwise the equation editor believes you entered multiplications. Also because of CAS, it seems that using lower case variables is not an option. Very cumbersome...
2. the solver demands that you have as many equations as variables. This may be right for linear equations but totally wrong in the vast majority of real life cases. I was trying psychometric equations for which 2 inputs suffice to achieve all other air conditions. 50g MES handles that smoothly.
3. in some occasions you may need macros. Here I need to export BASIC functions from Program to support this while the 50g will accepts RPL objects. While this is in reality conceptually identical, I find the RPL approach with objects in the same directory far more natural, and also RPL is more adapted to calculator than BASIC. Just a matter of opinion here...

Edit: I revisited my conclusion because this is not intended to be a flame against the Prime. I'm not an expert of the Prime and may be there are ways to achieve the same as the 50g but for now I haven't been able to.

[leprechaun]

I share these feelings and the problems! Especially 2 is a point. Variables between cas/home is an old topic.
Plus I think it is uncommon to have to duplicate the app rather than using one app with different Data sets.

As far as I unnderstand this is a result of the primes Design choice. Managment wanting a simple development (old codebase and parisses cas) and experts who are sure that students benefit from the prime as it is. I think therefore that my own dumbness is the reason for my diffuculties. I have the Hope that hp understands what many people desire and have problems with, work on that and finds a solution.
At the moment I find myself not having the courage to ask questions because it makes me feel even more idiotic. And many issues are difficult to put in a simple question.

[Gerald H]

(04-18-2015 09:41 AM)leprechaun Wrote:  I share these feelings and the problems! Especially 2 is a point. Variables between cas/home is an old topic.
Plus I think it is uncommon to have to duplicate the app rather than using one app with different Data sets.

As far as I unnderstand this is a result of the primes Design choice. Managment wanting a simple development (old codebase and parisses cas) and experts who are sure that students benefit from the prime as it is. I think therefore that my own dumbness is the reason for my diffuculties. I have the Hope that hp understands what many people desire and have problems with, work on that and finds a solution.
At the moment I find myself not having the courage to ask questions because it makes me feel even more idiotic. And many issues are difficult to put in a simple question.

I had very much the same feelings about the 38G, I couldn't believe the calculator was so bad, I kept thinking it was me who had missed something.

18 years later I realise just how useless the 38G was.

[Marcio]

(04-17-2015 09:13 PM)Tugdual Wrote:  2. the solver demands that you have as many equations as variables. This may be right for linear equations but totally wrong in the vast majority of real life cases. I was trying psychometric equations for which 2 inputs suffice to achieve all other air conditions. 50g MES handles that smoothly.

Tugdual,

Just to be clear, you're solving these equations sequentially, not simultaneously, right?

[Tugdual]

(04-21-2015 04:32 PM)Marcio Wrote:  

(04-17-2015 09:13 PM)Tugdual Wrote:  2. the solver demands that you have as many equations as variables. This may be right for linear equations but totally wrong in the vast majority of real life cases. I was trying psychometric equations for which 2 inputs suffice to achieve all other air conditions. 50g MES handles that smoothly.

Tugdual,

Just to be clear, you're solving these equations sequentially, not simultaneously, right?

If I had to do that manually, yes it would be sequential and of course equations are redundant enough to always find all variables providing 2 are known.

[ndzied1]

I too have found the 50g MES much better for my needs than the Prime solver. With the 50g MES I can set up an environment for experimentation with a collection of related equations where I bounce around putting in different numbers as I investigate things.

For instances, I have a series of equations related to hydraulic cylinder calculations.
{'A1=pi*D1^2/4' 'A2=pi*D2^2/4' 'AA=A1-A2' 'Push=Pr*A1' 'Pull=Pr*AA' 'Ve=Q/A1' 'Vr=Q/AA' 'Vre=Q/A2' 'Te=s/Ve' 'Tr=s/Vr' 'Tre=s/Vre' } Where:

A1-> Bore Area
A2 -> Rod Area
AA -> Annular Area
D1 -> Bore diameter
D2 -> Rod diameter
Push -> Pushing Force
Pull -> Pulling Force
Pr -> Pressure
Ve -> Velocity Extending (normal circuit)
Vre -> Velocity Extending (regeneration circuit)
Vr -> Velocity Retracting
Q -> Fluid Flow
s -> Cylinder Stroke
Te -> Time to fully extend (normal circuit)
Tre -> Time to fully extend (regeneration circuit)
Tr -> Time to fully retract

When working, I generally know which combinations of input data are required to solve for something (if not the 50g lets me know). I can use this if I only want to solve for push force in which case I only need to enter D1 and Pr. The MES doesn't care that I haven't entered all the variables. But then, for instance, I solve for push force and want to then look at the pull force. I don't have to re-enter pressure, I just enter D2 and solve for Pull. Then I want to know how much flow I need to extend the cylinder 10 inches in 5 seconds so I enter s=10 and Te=5 and solve for Q. Then maybe I get 6.25 gpm for flow but I realize that the standard pump only puts out 6 gpm so I enter that and go back and see how that effects my extend and retract times. Hopefully you get the picture. It is a wonderful experimental environment within which to bounce back and forth when working out a problem.

And notice my equations do not have conversion factors in them. That is because the 50g lets me attach units to all the variables I use in the MES. It takes care of the conversions for me. So when I get some answer, it has units on it and then I can jump to the unit menu to convert my 6 gpm to 22.7 L/min for my EU friends.

Now that is wonderful tool in my humble opinion!

[leprechaun]

Wonderful answer! Amen to that. I think by given ganz example from your practice it geht's clearer to everyone what is meant by school tasks an what people Miss from the mes.
However adding something like the old mes is a doable thing If You think of making the dual system home/cas interact more smoothly.
At least it is what my intuition would Tell me. Maybe HP surprises us with such a Tool! (Fitted into the prime's system. ( It is still hard to understand the people who prefer the fixed variable names while cas has not such needs)