How to Plot Multiple Lines in MATLAB (2024)

Plotting multiple lines in MATLAB is a common task that can be used to visualize data, compare results, and identify trends. There are a few different ways to plot multiple lines in MATLAB, each with its own advantages and disadvantages. In this article, we will discuss the three most common methods for plotting multiple lines in MATLAB:

• The plot() function
• The hold() function
• The subplot() function

We will also provide examples of each method so that you can see how they work in practice. By the end of this article, you will be able to plot multiple lines in MATLAB with ease.

In MATLAB, you can plot multiple lines in the same figure by using the `plot()` function. The `plot()` function takes a list of data points as input, and it will plot a line connecting the points. You can also use the `plot()` function to plot multiple lines by passing in multiple lists of data points.

In this tutorial, you will learn how to plot multiple lines in the same figure in MATLAB. You will also learn how to adjust the appearance of the lines, such as the color, width, and style.

Plotting multiple lines in the same figure

To plot multiple lines in the same figure, you can use the following steps:

1. Create a figure in MATLAB.
2. Add multiple lines to the figure.
3. Adjust the appearance of the lines.
4. Save the figure.

Creating a figure in MATLAB

To create a figure in MATLAB, you can use the `figure()` function. The `figure()` function takes a number of optional arguments, but the most important argument is the `’Name’` argument. The `’Name’` argument specifies the name of the figure.

For example, the following code creates a figure named `’MyFigure’`:

matlab
figure(‘Name’, ‘MyFigure’);

Adding multiple lines to the figure

To add multiple lines to a figure, you can use the `plot()` function. The `plot()` function takes a list of data points as input, and it will plot a line connecting the points. You can also use the `plot()` function to plot multiple lines by passing in multiple lists of data points.

For example, the following code plots two lines in the same figure:

matlab
x = [1, 2, 3, 4, 5];
y1 = [1, 4, 9, 16, 25];
y2 = [2, 5, 10, 17, 26];

plot(x, y1);
plot(x, y2);

The resulting figure will look like this:


Adjusting the appearance of the lines

You can adjust the appearance of the lines in a figure by using the following properties:

• `’Color’`: The color of the line.
• `’LineWidth’`: The width of the line.
• `’LineStyle’`: The style of the line.
• `’Marker’`: The marker type for the line.

For example, the following code changes the color of the first line to red, the width of the second line to 3, and the style of the third line to dashed:

matlab
x = [1, 2, 3, 4, 5];
y1 = [1, 4, 9, 16, 25];
y2 = [2, 5, 10, 17, 26];
y3 = [3, 6, 12, 19, 28];

plot(x, y1, ‘Color’, ‘red’);
plot(x, y2, ‘LineWidth’, 3);
plot(x, y3, ‘LineStyle’, ‘–‘);

The resulting figure will look like this:


Saving the figure

To save a figure, you can use the `savefig()` function. The `savefig()` function takes a number of optional arguments, but the most important argument is the `’File’` argument. The `’File’` argument specifies the file name of the figure.

For example, the following code saves the figure to a file named `’MyFigure.png’`:

matlab
savefig(‘MyFigure.png’);

Plotting lines with different styles

In addition to changing the color, width, and style of the lines, you can also add markers to the lines. Markers are small symbols that are placed at each data point.

To add markers to a line, you can use the `’Marker’` property. The `’Marker’` property takes a string as input, and the string specifies the type of marker.

For

Plotting lines with different data

Matlab provides several ways to plot lines with different data. In this section, we will show you how to plot data from a file, an array, a function, and a mathematical expression.

How to plot data from a file

To plot data from a file, you can use the `plot` function. The `plot` function takes two or more vectors as input, and it will plot each vector as a separate line. For example, the following code plots the data in the file `data.txt` as two lines:

matlab
% Read the data from the file.
data = load(‘data.txt’);

% Plot the data.
plot(data(:, 1), data(:, 2));
hold on;
plot(data(:, 3), data(:, 4));
hold off;

The `hold on` and `hold off` commands are used to keep the lines from being overwritten.

How to plot data from an array

To plot data from an array, you can use the `plot` function. The `plot` function takes two or more vectors as input, and it will plot each vector as a separate line. For example, the following code plots the data in the array `data` as two lines:

matlab
% Create an array of data.
data = [1, 2, 3; 4, 5, 6];

% Plot the data.
plot(data(:, 1), data(:, 2));
hold on;
plot(data(:, 3), data(:, 4));
hold off;

How to plot data from a function

To plot data from a function, you can use the `plot` function. The `plot` function takes two or more vectors as input, and it will plot each vector as a separate line. For example, the following code plots the data from the function `f(x)` as a line:

matlab
% Define the function.
function y = f(x)
y = x^2;
end

% Plot the function.
x = linspace(-1, 1, 100);
y = f(x);
plot(x, y);

How to plot data from a mathematical expression

To plot data from a mathematical expression, you can use the `plot` function. The `plot` function takes two or more vectors as input, and it will plot each vector as a separate line. For example, the following code plots the data from the mathematical expression `y = x^2` as a line:

matlab
% Define the mathematical expression.
y = x^2;

% Plot the expression.
x = linspace(-1, 1, 100);
y = f(x);
plot(x, y);

Plotting lines with error bars

Error bars are used to represent the uncertainty in your data. To add error bars to a line plot, you can use the `errorbar` function. The `errorbar` function takes four or more vectors as input, and it will plot the data as a line with error bars. The first two vectors are the x- and y-coordinates of the data points. The third and fourth vectors are the lower and upper limits of the error bars. For example, the following code plots the data in the file `data.txt` with error bars:

matlab
% Read the data from the file.
data = load(‘data.txt’);

% Plot the data with error bars.
errorbar(data(:, 1), data(:, 2), data(:, 3), data(:, 4));

The `errorbar` function has several options that you can use to customize the appearance of the error bars. For example, you can use the `capsize` option to change the size of the error bar caps, and you can use the `elinewidth` option to change the width of the error bar lines.

How to change the error bar style

You can change the style of the error bars by using the `linestyle` option. The `linestyle` option takes a string as input, and it specifies the style of the error bar lines. For example, the following code

Q: How do I plot multiple lines in MATLAB?

A: To plot multiple lines in MATLAB, you can use the `plot()` function. The `plot()` function takes a list of x-values and y-values as input, and it will plot a line for each pair of x-values and y-values. For example, the following code will plot two lines:

x = [1, 2, 3, 4];
y1 = [1, 4, 9, 16];
y2 = [2, 5, 10, 17];

plot(x, y1);
plot(x, y2);

Q: How do I change the line colors in MATLAB?

A: To change the line colors in MATLAB, you can use the `color()` function. The `color()` function takes a color name or a number as input. For example, the following code will change the color of the first line to red:

plot(x, y1);
color(‘red’);
plot(x, y2);

Q: How do I add labels to my lines in MATLAB?

A: To add labels to your lines in MATLAB, you can use the `xlabel()` and `ylabel()` functions. The `xlabel()` function sets the label for the x-axis, and the `ylabel()` function sets the label for the y-axis. For example, the following code will add labels to the two lines in the previous example:

plot(x, y1);
xlabel(‘x-axis’);
ylabel(‘y-axis’);

plot(x, y2);

Q: How do I change the line width in MATLAB?

A: To change the line width in MATLAB, you can use the `linewidth()` function. The `linewidth()` function takes a number as input, which represents the line width in points. For example, the following code will change the line width of the first line to 3 points:

plot(x, y1);
linewidth(3);
plot(x, y2);

Q: How do I add a legend to my plot in MATLAB?

A: To add a legend to your plot in MATLAB, you can use the `legend()` function. The `legend()` function takes a list of strings as input, which represent the labels for the lines in the plot. For example, the following code will add a legend to the plot in the previous example:

plot(x, y1);
xlabel(‘x-axis’);
ylabel(‘y-axis’);

plot(x, y2);

legend(‘Line 1’, ‘Line 2’);

In this tutorial, we have learned how to plot multiple lines in MATLAB. We first discussed the basic syntax for plotting a single line, and then we showed how to add additional lines to the same plot. We also covered how to change the line colors, styles, and widths. Finally, we showed how to add labels to the axes and legends to the plot.

We hope that this tutorial has been helpful. Please feel free to leave any questions or comments below.