Getting Started

Overview of MATLAB Plotting

MATLAB provides a wide variety of techniques to display data graphically. Interactive tools enable you to manipulate graphs to achieve results that reveal the most information about your data. You can also annotate and print graphs for presentations, or export graphs to standard graphics formats for presentation in web browsers or other media.

For More Information    Graphics and 3-D Visualization in the MATLAB documentation provide in-depth coverage of MATLAB graphics and visualization tools. Access these topics from the Help browser.

The Plotting Process

The process of visualizing data typically involves a series of operations. This section provides a "big picture" view of the plotting process and contains links to sections that have examples and specific details about performing each operation.

Creating a Graph

The type of graph you choose to create depends on the nature of your data and what you want to reveal about the data. MATLAB predefines many graph types, such as line, bar, histogram, and pie graphs. There are also 3-D graphs, such as surfaces, slice planes, and streamlines.

There are two basic ways to create graphs in MATLAB:

• Use plotting tools to create graphs interactively.

• See Examples -- Using MATLAB Plotting Tools.

• Use the command interface to enter commands in the Command Window or create plotting programs.

• See Basic Plotting Functions.

You might find it useful to combine both approaches. For example, you might issue a plotting command to create a graph and then modify the graph using one of the interactive tools.

Exploring Data

Once you create a graph, you can extract specific information about the data, such as the numeric value of a peak in a plot, the average value of a series of data, or you can perform data fitting.

For More Information    See Data Exploration Tools and The Basic Fitting Interface in the MATLAB documentation.

Editing the Graph Components

Graphs are composed of objects, which have properties you can change. These properties affect the way the various graph components look and behave.

For example, the axes used to define the coordinate system of the graph has properties that define the limits of each axis, the scale, color, etc. The line used to create a line graph has properties such as color, type of marker used at each data point (if any), line style, etc.

Note that the data used to create a line graph are properties of the line. You can, therefore, change the data without actually creating a new graph.

See Editing Plots.

Annotating Graphs

Annotations are the text, arrows, callouts, and other labels added to graphs to help viewers see what is important about the data. You typically add annotations to graphs when you want to show them to other people or when you want to save them for later reference.

For More Information    See Annotating Graphs in the MATLAB documentation or select Annotating Graphs from the figure Help menu.

Printing and Exporting Graphs

You can print your graph on any printer connected to your computer. The print previewer enables you to view how your graph will look when printed. It enables you to add headers, footers, a date, and so on. The page setup dialog lets you control the size, layout, and other characteristics of the graph (select Page Setup from the figure File menu).

Exporting a graph means creating a copy of it in a standard graphics file format, such as TIF, JPEG, or EPS. You can then import the file into a word processor, include it in an HTML document, or edit it in a drawing package select Export Setup from the figure File menu).

For More Information    See the print command reference page and Printing and Exporting in the MATLAB documentation or select Printing and Exporting from the figure Help menu.

Saving Graphs to Reload into MATLAB

There are two ways to save graphs that enable you to save the work you have invested in their preparation:

• Save the graph as a FIG-file (select Save from the figure File menu).
• Generate MATLAB code that can recreate the graph (select Generate M-File from the figure File menu).

FIG-Files.   FIG-files are a binary format that saves a figure in its current state. This means that all graphics objects and property settings are stored in the file when you create it. You can reload the file into a different MATLAB session, even if you are running MATLAB on a different type of computer. When you load a FIG-file, MATLAB creates a new figure in the same state as the one you saved.

Note that the states of any figure tools (i.e., any items on the toolbars) are not saved in a FIG-file; only the contents of the graph are saved.

Generated Code.   You can use the MATLAB M-code generator to create code that recreates the graph. Unlike a FIG-file, the generated code does not contain any data. You must pass the data to the generated function when you run the code.

Note that studying the generating code for a graph is a good way to learn how to program with MATLAB.

For More Information    See the print command reference page and Saving Your Work in the MATLAB documentation.

Graphics

Graph Components

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