The Function Editor

The function editor contains normally 4 panels. If the template does not define parameters, or input matrices or output matrices, the related panel is missing.
Here are the panels:

Template Info Panel

It contains some information about the template from which the function is built. It shows the fields:

Info: a description of the function
Input matrices: the minimum and maximum amount of input matrices. The minimum amount of matrices defines the number of mandatory matrices. The matrices over the minimum to the maximum amount are optional.
Output matrices: the minimum and maximum amount of output matrices.

Input Matrices Panel

It contains a table where you can enter the matrices that are required as input of the function. For example, in case of the plus (+) function, you need as input the two matrices to sum. When the editor for a new function is opened, the list contains a line for each needed input matrix.

Foe each line (each input matrix) the first two columns show: a name that identifies the matrix in the function (for example “addendum1” in the plus function) and the required type of the matrix and.
The type of the required matrix can be NUMERIC, TEXT, DATE, BOOLEAN or ANY.
ANY means that that input matrix can be of any type but you need to choose one when creating the function. ANY is used when the template is generic, can work with any type of matrix, for example the “tostring” template which converts a matrix of any type to a text matrix.

To see a description of the function in the selected row click on the Description button. A message box with the description appears. To set an input matrix you select the matrix and click on the Set Matrix button, which opens the matrix selection dialog.
Double-clicking on a table row has the same effect of the Set Matrix button.

Alternatively you can drag&drop the matrix from the matrices tree view in the project: select the matrix in the matrices tree view with the left button of the mouse and, keeping the mouse button pressed, move the cursor to the line of the input matrices panel that you want to fill, and release the left mouse button.

In both cases the matrix fills the line: the “Chosen Matrix” column of the line, which was initially empty, is filled with the name and the package of the chosen matrix.

Clicking the Clear Row button the selected row is cleared: any matrix that was set for this row with the Set Matrix button is removed from it, leaving the “Chosen Matrix” field of the row empty.

It is not told that all the input matrices lines need to be filled. Some of the matrices can be optional. For example you could make a function that sums all the input matrices, being them a number between 2 and 32. In this case the first 2 matrices are mandatory (need to be filled) but the last 30 are optional. You can know which matrices are mandatory and optionals looking at the minimum-maximum amount of input matrices in the Template Info panel. When you save the function, the input matrices list must contain at least the minimum number of matrices, at most the maximum. The input matrices lines can be filled in any order, but at the end the list of filled matrices must be consecutive, without holes.

The Output Matrices Panel

It contains a table where you can enter the matrices required as the result of the function. To fill the output matrices lines you need to select the line to fill and click on the Set Matrix button.

This is what happens if you are entering a standard output matrix (callback column empty), clicking on the Set Matrix button:
If the matrix definition type is ANY, the actual type of the matrix is requested through the matrix type dialog.
After that you need to give a name-package to the matrix using the name-package dialog. Since these matrices are the result of the function, Matrex verifies that they don't exist when the function is built (if they exist they have been produced by another function or with the matrix editor). If everything is ok they are created when the function is saved.

If the callback column contains the value "Yes", the output matrix is callback.
In this case, the matrix needs to be already in the project when the function is added, and it must be a base matrix (not output of any other function).
The Set Matrix button opens the matrix selection dialog to select the callback matrix: since the matrix must be already in the project, it must be selected from the base matrices of the project.

Also here you have mandatory and optional matrices. You can know which matrices are mandatory and optionals looking at the minimum-maximum amount of output matrices in the Template Info panel. The same considerations seen for the optional input matrices can be done here.

Parameters Panel

It Contains some constant parameters to the function. Differently from the input matrices, they are simple fields, not matrices and they don't change during the life of the function. Also the parameters can be of different types, NUMERIC, TEXT, DATE or BOOLEAN.
Some parameters are entered as text, other are selectable in a dropdown list.

When the parameter if of TEXT type you can use the ... button to open a special editor to enter it.

The editor type depends by how this parameter is declared in the template:

If it is declared as NORMAL_TEXT, the editor is a multiline text box, that simplifies editing small texts.
If it is declared as FILE, it is assumed that the text must be the path of a file, so you can select it in an Open File dialog.

The tooltip of the text box shows anyway the whole text.

Parameters of DATE type can be entered in the text box in the format decided in the GUI settings, or, by clicking on the ... button, with the help of the date/time picker dialog.

Parameters can be selected from a dropdown list instead of being entered in a text box, if the template requires it. The dropdown list looks like this:

Like with the input and output matrices, some parameters are mandatory, some are optional. You can distinguish an optional parameter because the background of its text is gray, not white. To close the editor, you can:

click on the Cancel button on the bottom of the editor. In this way you close the editor without saving the content of the function (you need to confirm this choice).
click on the Save button on the bottom of the editor. In this way you save the content of the function and close the editor. To do that, you need to enter the name and the package of the new function in the name-package dialog, in the same way as with the matrices.
Only if the function is complete (all the mandatory input matrices, output matrices, parameters have been set), it is possible to save. If these conditions are not satisfied an error appears (“Not enough...”) and it is possible to fix the problem.
When you save it, the function is calculated and all the output matrices are created (or overwritten if you edited an existing function with the same output matrices).