Quick Statistics Application

Stellaferox

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Hi All,

I've rewritten an earlier application which calculates all the possible scores of probability, X², Student-t and F-distributions from the input and vice-versa. Also it shows a nice graphical view of the above, below, in between and outside probabilities of a give z-score.
I realise this is only for the statistical geeks like me, but I find it rather usefull in quickly computing the wanted scores.
Have fun :sign0060:
Any feedback is greatly appreciated
thnx in advance
Marc
 

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derez

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Thank you, one never knows when in need for some statistics calculations (and the old schaum book is no longer available...)

line 552 needs change of PI to Cpi
 

dlfallen

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Glad to see another stathead out there!

Your program is similar to my Probability Calculator (see page two of this forum). Mine was designed to run on a WM cell phone, hence the popup number pad.

Two questions about your program: (1) when going from p(z) to z I'm getting the wrong answer. For example, for alpha = .05 (1-tailed) the program returns 2.271 -- the correct answer, of course, is 1.645. Also, the program will not allow me to enter an alpha value for t, so I cannot lookup the value of t associated with a given alpha, df.

You might also be interested in my binomial calculator on the last page of this forum.
 

Stellaferox

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Hi,

LOL, always nice to meet a fellow stathead!

I adjusted the program according to your remarks. Thanks for your input. Anything is welcome. I uploaded the new program in my original post.

Your program was actually the push to update my old Turbo-Pascal and Delphi programs!
Thank you for that. At the moment I am working on several programs, also one on statistics; more specific, a program that creates 2 huge populations and then let you choose of which population you want to take samples. It then computes the data according.
If you encounter more problems, please let me know.
Marc
 

dlfallen

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Hi,

I tried running your updated code (on the desktop), but now I receive the error message below.

I have a few Stat programs I may convert sometime, but there seems to be little interest so I have them on the back burner. My main focus right now is a GPS app, and then I may finish off my Let It Ride game.

Dave
 

dlfallen

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A couple of more items. I hope you don't think I am being hypercritical, I'm just trying to help.

Why does the button in the upper right-hand corner of the main form now display "$" instead of "Calc"?

For the t, F, and Chi-square distributions, the random variable textbox is bottom of the group, and the alpha box is at the top. For the Z distribution, the order is reversed. This is confusing, but easy to fix.

I like the graph page a lot. It could benefit from a "calc" or "graph" button. Currently, if you enter a new value the only way to redraw the graph is to check another radio button and then recheck the one of interest.

You might consider having the last calculated values from the main form automatically entered into the appropriate places on the graph form. Then, the user can simply switch to the graph page and see the results.

Dave
 

Stellaferox

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Dave,

Quite frankly, I appreciate your input very much because not a lot of people know or care enough about the subject to give feedback, so please continue to do so!

To address your comment:

- I changed it into a "$" because there wasn't any more space left to display "Calc". I thought about showing it in a pull-down menu but I wanted quick access. I guess if you rearrange the buttons a bit tighter, more space is left to display a proper button.

- About the order of the boxes: you're right. It is because I regard the z-score as basic to the Probability-scores. It is of course no problem at all to reverse the boxes and the cA.Checked line in the sub.

- About the graph-page: right again. I implemented this Graph page from an earlier written (stand-alone) program to calculate these scores. You don't have to check another radiobutton first, just rechecking the wanted button will do, but I agree that a "Calc" button here would suit in fine. I will do so.

- About you last remark: that is already on my to-do list. I also want to make a faster redrawing routine. This "Floodfill"routine is from earlier days when no real Floodfill-routine was available. On the desktop it works fast enough but on a pocket pc the routine is to slow.

The problem with most of my programs (or is it really my problem?) is that the moment functionality works I don't care very much anymore about presentation and displays. It is good therapy to make an extra effort for this, so thnx agian. In the following days I willl adjust the lines but feel free to adjust anything you'd like yourself. At the moment I am working on a program which shows the exact time of the sun coming up and going down world-wide, another stat-program I mentioned earlier and a game.

Marc
 

Stellaferox

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Hi Klaus,

Yes I know. In fact I already included the library but haven't done the updating yet. Too many other things that are also fun...:sign0060:
Marc
 

Stellaferox

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Thnx Ariel, will look into it.
In the meantime I restyled the buttons and now the scores from the Main page are transferred to the Graph page. I updated the original post and file.
Floodfill routine to be done next.....
Marc
 

dlfallen

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Marc, could you provide us with the modified version? You were probably waiting until you did the floodfill changes, but in the meantime perhaps we could give you some useful feedback on the other changes.

-Dave
 

Stellaferox

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Hi Dave,

The most recent version is uploaded in the first post. I am thinking of working on the floodfill routines this weekend.
Have fun
Marc
 

dlfallen

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Marc:

I absolutley LOVE the interaction between the calculation page and the graph page. Well done! :)

Do you consider this freeware? The reason I ask is that I will be teaching an intro Statistics class soon and I may want to share the program with students for the purpose of checking their own homework. We stopped using square root tables long ago. I don't understand why we continue to use textbook tables for questions relating to areas under the curve for the four distributions covered by your program.

-Dave
 

Stellaferox

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Hi Dave,

Yes it is freeware. You can modify it any way you want. It is still not quite the way I want it though.
If you have any ideas to speed up the performance on pocket pc's I'd be glad to hear it!
Marc
 

Stellaferox

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@Dave

Hi Dave,

I adjusted the program a little bit. I don't know whether you like it.
- There are now "icons" for the probabilities on the Main form.
- By changing the icons the probability is adjusted in the according z-score and also on the second Graph form.

I didn't succeed in using the Floodfill routine as it kept saying I used out of bounds parameters. Also I don't think the routine will be faster then my Linedraing-routine. Please prove me wrong on this! (Agraham?)
The routines are AreaFill (and AreaErase if you want).

Have fun with it and tell me what you think!

regards,

Marc

PS: Somehow I couldnt re-edit the first post on this mobile laptop so I included the adjusted sbp-file here
 

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