First off: No need to shout. Normal size font will do.
Add to Valery's reply:
Mathcad 15 comes standard with extra functionality built-in, that you had to buy separately for Mathcad 11: Modules such as Signal processing (probably contains the phase and phasecor functions), Data analysis, Image processing and Wavelets. Note that Mathcad 11 Enterprise Edition does contain all these modules.
Mathcad 11 cooperates with MathConnex, a module that allows interprocess communication between Mathcad and other software, which would allow you to build a feedback system. MathConnex existed since Mathcad 8, or earlier. I don't know when it was dropped, but I bet that PTC sees no use for it.
Mathcad 15 SUCs. Let me explain: In Mathcad up to and including version 11 you can write a function like this:
That is, the function will return a unit that depends on its parameter. In Mathcad 12 that sort of functionality was broken by a new feature named Static Unit Checking (SUC), and it remained in all versions of (real) Mathcad. (I've attached the worksheet, you can see for yourself what error message this produces in Mathcad 15.)
It's not so much that this specific function will not work in Mathcad 15, but not being able to do this, also prevented some really useful applications where the unit of a result cannot be predicted.
(Fortunately SUC did not make it into Prime:
But then, Prime has it's own features, which are not under discussion here...)
Mathcad 11 was developed by MathSoft. Mathcad 15 (probably) was written by Mathsoft engineers after PTC bought MathSoft.
Mathcad 11 file format (.mcd) is compressed data. Mathcad 15 (.xmcd) is xml data. I remember complaints that it would 'take ages' for Mathcad 15 to load a sheet, while the .mcd sheet with the same contents will fly in like a breeze in Mathcad 11.
Luc
