Ok, I added this exercice to react to some comments and reviews from the AppStores. (Note that I could answer reviews by giving a review to my own software, but I won't do that...)

Let's begin with a formula as simple as x^2.

With touchplot up to 2.1, you had to realize that this formula is a power, more precisely the power of x to the exponent 2, and you had to do this :

the principle of direct polish notation being indeed that you write the operator before its arguments. (reverse polish notation puts the operator after its arguments, so on a RPN calculator, you would compose instead x,2 then ^...)

The same goes for a sum, a product, a quotient.

I don't suppose it would take a very long time for someone who read the documentation.

That being said, things are now a bit different with touchplot 2.2 (and subsequent versions of course), because one can now do instead :

Difficult, hum ? (The old way is still possible, of course...)

Now, suppose you want to enter exp(x)+x, you would indeed have to do, before 2.2 version of touchplot :

because this expression is a sum, the sum of exp(x) and of x. (It sounds complicated, maybe, but the graphical display of the formula makes it quite easy to follow, after hitting +, you get something like this : ■+■, then exp(■)+■, then exp(x)+■ then finally exp(x)+x...)

You can still do this with versions >= 2.2 of touchplot, but you might do as well :

Now, be aware that for little parts of your formula, you still have to use polish notation, or use the selection scheme introduced in TouchPlot 3.2. See the page about the new 3.2 formula editor.

If you take the time to do the little three more exercices following this one, I think you'll have everything you need to do some work, experiment, and learn with touchplot.

And if you read the documentation on this website, and did the exercices, and still have a problem, fell free to send me an email and ask for guidance.