# I do it like this in my spreadsheet. How I do it in Matrex?

This guide should help answering the questions that a traditional spreadsheets user would ask when it uses Matrex for the first time.

- Where is the spreadsheet?

Even if it is called spreadsheet application, Matrex does not use spreadsheets to enter data and formulas. The calculation unit of Matrex is the matrix (or vector), not the cell. Therefore having a big editor of individual cells does not make sense in Matrex.

To enter numbers in Matrex (or other type of data) use the Matrix Editor.

To display together the entered data and/or the calculation results with colors use the Presentation. A presentation is in priciple a read-only spreadsheet, built with matrices. - When I start Matrex I get this tall empty window. Where do I write the data ad formulas?

Matrex is organized in projects. A project is roughly equivalent to a workbook.

Matrex does not open a default project when it starts, like a traditional spreadsheet does: after you started Matrex you will need to create yourself a new project or open an existing one.

For example you can open a project example under the projects directory. - I opened a project. The window got filled with panels. What are they?

Matrex is not based on spreadsheets, but on matrices, functions, presentations, charts and timers,

Each project can contain many of these items so it makes sense to arrange them in a way that makes easy to find them.

Each of the panels, called tree, is equivalent to a file manager (e.g. Explorer). Like a file, each item has a name and all of them are structured in directories (packages) in the tree.

There is a tree for the matrices, a tree for the functions, a tree for the presentations... - You speak about 5 trees, but I only see 2 of them. Where are the others?

You can use the buttons on the top of the project view to show and hide trees.

Initially the project view displays only the matrices tree and the functions tree, which are the most used. - Ok, projects and trees. Still, I don't know how to enter data.

To enter a new matrix you open the matrix editor. Click in the matrices tree with the right mouse button. In the menu that appears select New Matrix and the type of matrix (or vector) you want to create. Enter the dimensions of the matrix (1 column for vectors) and start to write the data in the editor.

When you are finished, press the Save button and enter the name of the matrix and the package where you want to save it (e.g. dir1.dir2.mymatrix). The matrix gets saved in the matrices tree. - I added a pair of matrices. Where are the formulas?

A Matrex project contains functions. A function is equivalent to a formula composed by only one function call (e.g. abs(x) or mod(x,y)). Functions are applied on matrices and produces matrices as results.

Functions are based on templates. Templates are equivalent to function names. They define the algorithm calculating the function and the input/output parameters types. In our previous examples the templates are abs and mod. - How do I enter formulas (or was they called functions)?

You have two possibilities:- You enter one single function in a graphical way, with the function editor. Click in the functions tree with the right mouse button. In the menu that appears select New Function. Select the template for the new function, then choose input matrices and parameters and output matrices and save it.
- You
enter an expression using the expression parser. An expression is more
or less equivalent to a spreadsheet complex formula. The expression
parser parsers the formula and decomposes it in several functions and
intermediate matrices, which are saved in the project. To start the
expression parser, click in the functions
tree with the right mouse button. In the menu that appears select
Expression Parser, which open the expression parser wizard. Enter the expression and follow the steps of the wizard.

- With a traditional spreadsheet I have all the data in one sheet and I can print it. Can I do something similar in Matrex?

You can build presentations. A presentation looks like a spreadsheet, but cannot be edited directly. A presentation is a set of matrices, placed on a grid. Each matrix can have different text and background colors.

To build a presentation, click in the presentation tree with the right mouse button. In the menu that appears select New Presentation, which opens the presentation editor.

In a presentation, the matrices are in a spatial hierarchy: for example there is a root matrix, then a matrix on its left, one under it and so on. This insures that changing the size of one of the matrices the matrices under or on the left of it are moved and the presentation looks still correct.