Data Visualization in MATLAB

Graphical Objects

MATLAB offers a comprehensive suite of functions for creating various types of visualizations. These are built upon a foundation of graphical objects, including figures, axes, and individual plotting elements (lines, markers, text, etc.). Understanding the hierarchical relationship between these objects is crucial for effective chart manipulation.

Basic Plotting Functions

Fundamental plotting functions such as plot, scatter, bar, hist, and pie provide straightforward methods for creating common chart types. These functions accept data as input and automatically generate appropriate visualizations. Users can customize aspects like line styles, marker types, colors, and labels using various optional arguments.

Advanced Plotting Functions

For specialized visualizations, MATLAB provides more sophisticated functions. area creates area charts, stem generates stem plots, and errorbar displays data with error bars. More complex charts, like contour plots (contour, contourf), surface plots (surf, mesh), and 3D scatter plots (scatter3), are also readily available.

Customizing Charts

Titles, Labels, and Legends

Chart clarity is significantly enhanced by informative titles, axis labels, and legends. MATLAB provides functions such as title, xlabel, ylabel, and legend to add these elements. Text properties, including font size, style, and color, are easily adjustable.

Axis Limits and Scaling

xlim and ylim control the range of values displayed on the x and y axes, enabling tailored viewing of data. Functions like axis equal, axis square, and axis tight adjust axis scaling and aspect ratios.

Annotations and Text

text and annotation functions allow for adding text or other graphical elements directly onto the chart, enabling the highlighting of specific data points or regions.

Colormaps and Color Schemes

For visualizations involving color, MATLAB offers a wide range of colormaps (colormap) to enhance visual appeal and data interpretation. These can be customized or user-defined.

Working with Handles

Each graphical object in MATLAB has a unique handle, a numerical identifier. Handles allow for precise control over individual chart elements. They are accessed using functions like gca (get current axes) and gcf (get current figure). Properties of objects can then be modified using dot notation (e.g., gca.XLabel.String = 'New X-axis Label';).

Exporting Charts

MATLAB supports exporting charts in various formats, including common image formats (JPEG, PNG, TIFF) and vector graphics formats (SVG, EPS). The print function handles the exporting process, allowing specification of the file type and resolution.