# Matlab Contour Plot Options

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Contour plots are a powerful visualization tool for examining the relationship between variables in multi-dimensional data. In MATLAB, contour plots can be created using the `contour` or `contourf` functions. But, to create more visually appealing and informative plots, we can customize them even further by applying color maps and labels.

## Color Maps

MATLAB has a variety of color maps that can be used to enhance the visual appeal and convey additional information in contour plots. A color map is essentially a function that maps scalar data to colors. You can use MATLAB's built-in color maps or create your own custom color map.

To change the color map of a contour plot, use the `colormap` function after creating the plot. Here's an example:

``````[X, Y, Z] = peaks; % Create sample data
contourf(X, Y, Z); % Create filled contour plot
colormap(jet); % Apply jet colormap``````

Some popular built-in color maps include:

• `jet`: Varies smoothly from blue to green to red
• `parula`: The default colormap, with a blue to yellow to red transition
• `hsv`: Hue-saturation-value color map covering the entire color spectrum
• `gray`: Grayscale color map
• `hot`: Black to red to yellow to white transition

You can also create your own custom color map by defining a matrix of RGB values. Each row of the matrix represents a color, with columns corresponding to red, green, and blue components. Here's an example of creating a custom color map:

``````custom_colormap = [0 0 1; 0 1 0; 1 0 0]; % Blue, green, red
contourf(X, Y, Z);
colormap(custom_colormap);``````

## Labels

Adding labels to your contour plot can help convey important information about the data. In MATLAB, you can add contour line labels using the `clabel` function.

Here's an example of adding labels to a contour plot:

``````[C, h] = contour(X, Y, Z);
clabel(C, h);``````

The `clabel` function has several optional parameters to customize the appearance of labels, such as fontsize, label format, and text properties. Here's an example of customizing labels:

``````[C, h] = contour(X, Y, Z);
clabel(C, h, 'FontSize', 10, 'FontWeight', 'bold', 'Color', 'k');``````

In this example, the fontsize is set to 10, the font weight is set to bold, and the label color is set to black.

By combining these options for color maps and labels, you can create contour plots that are not only visually appealing but also informative and easy to read.

## FAQ

### How do I apply a colormap to a contour plot in MATLAB?

After creating your contour plot using `contour` or `contourf` functions, apply a colormap using the `colormap` function followed by the colormap of your choice, e.g., `colormap(jet)`.

### How do I create custom colormaps in MATLAB?

Create a custom colormap by defining a matrix of RGB values. Each row of the matrix represents a color, with columns corresponding to red, green, and blue components. Then apply it using the `colormap` function.

### How do I add labels to contour lines in MATLAB?

Use the `clabel` function after creating the contour plot using the `contour` function. When calling `contour`, store the output arguments `[C, h]` and pass them to the `clabel` function as `clabel(C, h)`.