From a

**mathematical expression** the

expression parser generates matrices and functions in a Matrex project. This is a powerful functionality in Matrex.

Once the expression parser has generated matrices and functions, the original expression gets lost. This is usally not a problem, since in the project there are all the matrices and functions (final and intermediate) that calculate the expression.

But sometimes you want to see again the original expression, to:

- see in one shot how a matrix has been calculated
- know exactly which matrices and functions have been generated by the expression, for example because you want to replace the original expression with a new one and therefore you need to remove them

Fortunately the

info window shows, among the rest:

- for a
**matrix**, the function that has it as result - for a
**function**, the input matrices

So it is possible, from the expression's result matrix, to find out the original expression

**navigating** to the source function, to the input matrices and so on.

But it is a lot of work to follow all the links among functions and matrices, expecially if the original expression is long.

To have a more valuable information, version 1.2 will contain a new functionality, called

**matrix source viewer**.

The idea is to have a window that shows this information as a

**textual expression**, with the same format used to enter an expression in the expression parser.

Suppose you entered the expression:

log(x + exp(y + z))

in the expression parser, and gave the name

*logres* to the result matrix.

If you open the

**matrix source viewer** on the

*logres* matrix, you'll see a window containing a text like:

log (

__logres.log__ )

Clicking on logres.log this part of the expression will be expanded and you'll have:

log (x +

__logres.exp__ )

Clicking on logres.exp this part of the expression will be expanded and you'll have:

log ( x + exp( y + z))

In this way with a limited number of clicks you'll have the original expression.

Also, a context menu on each item in the expression (excluded the parentheses) will open viewer or editor for that item.

Now the question is: why to see the original expression I need to click on links? Could it not appear as it was immediately?

The problem is that x, y and z could also be the result of other expressions and Matrex does not know which matrices are part of an expression and which are part of another.