Hello,
(SMath Studio version 0.88 is current as I write this.)
About Andrey's statement:
smath wrote:My idea is to combine (.) and ([) in one ([).
It might be worthwhile to keep these separate. What the computer does with A.x (at least in Mathcad) is different than with A[x
That is, A[x uses x as an index to select one element from A, but A.x names a variable which has nothing to do with the variable (matrix) A.
* The (.) is just part of the variable name, so that there is hardly any difference between A.x and Abx. There can be a worksheet that refers just to A.x, without variables A or x existing at all.
* On the other hand, ([) can be thought of as a function with arguments A and x that "does something" with A and x to get or set a value. Arguments A and x are required to exist as separate variables in order for A[x to be valid.
The previous paragraph might help with Radovan's concern about explaining the difference between ([) and (.) to students / new users.
Furthermore, maybe future versions of SMath Studio could have the following 2 formatting features:
1. ([) could be formatted with parentheses and an arguments separator, similar to the following (depending on localization):
(.) would be formatted as ([) (with one argument) is today, that is, without the parentheses ().
2. The "(" character could be disallowed in variable names (if it is not already).
As a result, someone looking at an SMath Studio worksheet could tell at a glance whether each subscript was a ([) or a (.) That is, ([) would have parentheses and (.) would not.
I think that combining the 2 kinds of subscripts into one could cause problems. For example, suppose the user has a matrix called A but also wants to define a scalar called A.x:
If (.) were separate from ([), then (.) could be used in this example, and there would be no error.
It seems to me that an expression like the following (using the formatting features suggested above) could still be evaluated (differentiated) just fine if (.) were added to SMath Studio:
According to the formatting features suggested above, the subscripts in that expression would be ([)
I assume that Andrey mentioned this expression just to point out that SMath Studio has the potential to be more versatile than Mathcad when it comes to subscripts.
If I am misunderstanding, maybe someone can clarify for me.