Content

Concepts

Matrix:


A rectangular block of numbers, texts, dates or booleans. Can be composed by only one column or row, in which case it is equivalent to a vector. It can be also composed by only one cell, in which case it is equivalent to a single number, text, date or boolean.
Matrex optimizes the calculations with matrices with only one column, called vectors. Instead matrices with one row are considered standard. Therefore using matrices with one column gives better performances than using matrices with one row.
To obtain a vector from a matrix with only one row, you need to use the transpose function.
The contained cells are all of the same type (number, text, date or boolean), so you can speak of numeric matrices, text matrices, date matrices or boolean matrices.
The content of a matrix should be homogeneous, which means that all the contained cells contain the same kind of information, like the values in a column of a database table.

Used in: Matrix Editor, Matrix Viewer.



Base Matrix:

A matrix that has been created with the matrix editor and therefore is not output of any function.
A base matrix can be edited and manually changed, a calculated matrix cannot.
This concept is very important in Matrex, because base matrices represent the initial parameters of all the calculations in a project.

Function:

The equivalent of a function used in a spreadsheet formula. Combines matrices to obtain matrices. If one of the input matrices changes, the function is recalculated (exactly how it happens in  a spreadsheet).

Function

Functions cannot contain composite formulas. It is anyway possible to enter composite formulas in Matrex: the expression parser translates formulas in a set of functions and intermediate matrices which are added to the functions and matrices trees in the project.

Used in: Function Editor, Function Viewer. 



Parameters:

Some functions need some “non matrix” parameters. For example the “query” function that queries the database and returns the result set as a set of vectors, needs the SQL query text as parameter.

Tree:

Concept similar to the “files tree” that we are used to see in a file system browser, like for example “Explorer” in Windows and “Nautilus” in Linux. Instead of the files we have matrices, functions, presentations.... The absolute path of the “directory” containing an item is called the package of the item, for example “/market/fonds/quotations”.
In a tree you can add items, delete them, move them from one package to the other,  rename them and all the other operations you are used to in a file system browser.

Used In: Trees.


Function Template:

When you add a function to a project, you need to build it from a template. The template is in some way the “structure” of the function, without data (the parameters and the input and output matrices).
A template specifies:

For example there is the “plus” function template for the sum of matrices and the “average” template  for the average of a matrix.
You can add a template in your machine or in a Matrex server, specifying parameters, input and output matrices definitions, and the code that has to be executed to calculate the function. The code can be written in Java (Matrex is also written in Java) or in a JVM scripting language. For version 1.0 we chosen as scripting language Jython.

Used in: Template Editor, Template Tree.




Thread:

Is the unit of execution in which a function transforms its input matrices to the output/result matrices. It can be executed in parallel with other threads, in the same time.
Using threads can improve the overall performance of the calculation, because complex functions are calculated in the same time as other functions and don't get the control of the GUI and in general of the whole system.

Timer:

Executes a function periodically. Used for example to:

Used in: Timer Editor

Presentation:

Very similar to the concept of spreadsheet, but only used to show the data, not to change it.  It is a big grid covered with the matrices and texts you chosen to add to it, in the foreground and background colors you want.
When a matrix changes its content, the presentation shows the changes.

Used in: Presentation Editor, Presentation Viewer.


Chart:

Equivalent to a chart in a spreadsheet application, gets some matrices as input and shows them as a 2D (for vector­like matrices) or 3D chart.

Used in: Multiseries Chart Editor, Chart Viewer, Chart Tree.


Project: 

Set of matrices, functions, presentations, charts and timers used for a common purpose. Matrex works by projects, which means that to work with matrices, functions etc. you need to create a project that contains the

Used in: Main Window, Other Menus.


Project item:

A matrix, function, presentation, chart or timer.

Item:

A project item or a template. In other words, anything that can be displayed in a tree and can be edited in an editor.

Machine:

The application that actually calculates the functions.
Can be a Matrex desktop application (called local) or a Matrex server (from version 2.0), used by the desktop applications (clients) to share projects.
When you open a project, you open it in a specific machine and it is the machine that recalculates its functions.

Used in: Main Window, Other Menus.


Callback matrix:

A callback matrix is a matrix that is, directly or indirectly, both input and output of the same function.
This is only possible with special functions, also called callback, that have a callback output matrix.
When the function is calculated, the matrix is updated (because it is output of the function) and for this reason it causes the function recalculation; which again updates the matrix, which again causes the function recalculation and so on.
The concept of callback function is equivalent to the one of recursive function, since it continues to call itself until some conditions are reached.

Used in: Function Editor.