# Merge 3 FFT Spectrum Graphs in MATLAB - Step-by-Step Guide

• MATLAB
• RK10
In summary, to merge 3 FFT spectrum graphs into one, you can use the subplot command in MATLAB. First, open an empty figure and select "New Subplots" from the Figure Palette. Then, add data to each of the three 3D axes and the graphs will be merged into one figure. This can also be implemented in code using the subplot command.

#### RK10

How can we merge 3 FFT spectrum graphs in one as shown in the picture?
AND THANK YOU

I have written the codes for the 3 spectrums but need to join them as shown.

#### Attachments

• 3D.PNG
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Okay here are the steps you need to follow:

Let's say you have the following data with you.

X,Y : Value for x,y axes for all the graphs.
Z1 : Value of Z for the first graph
Z2 : Value of Z for the second graph
Z3 : Value of Z for the third graph

Steps:

1. Open an empty figure by typing "figure" in the command window.
2. Click on the window like structure given above in the tool bar just below "Help" (you must have used to type title of the figure and all).

3. Now when you open it, then either you can see "Figure Palette", if yes then proceed to next 4, otherwise click on the Desktop, and select Figure Palette from there (same as you do to see command window, workspace etc).

4. There you can see "New Subplots", select 3D Axes as many as you want.
5. Now once you got three 3D axes on the figure, you can add data to them by right clicking the axes.
6. Hope it works.

By the way nice figures :)

To implement this in code you'd use the subplot command,

figure;
subplot(1,3,1) % splits the figure into three side-by-side figures and selects the first
[put code to generate image 1 here]
subplot(1,3,2)
[image 2]
subplot(1,3,3)
[image 3]

## 1. How do I merge three FFT spectrum graphs in MATLAB?

To merge three FFT spectrum graphs in MATLAB, you can use the "hold on" command to plot all three graphs on the same figure. Then, use the "legend" command to add a legend to the graph, labeling each graph accordingly. Finally, use the "grid" command to add grid lines for better visualization.

## 2. Can I merge FFT spectrum graphs with different sampling rates?

Yes, you can merge FFT spectrum graphs with different sampling rates. However, it is important to note that the sampling rates should be compatible with each other. This means that the sampling rates should be related by an integer factor for the graphs to be merged accurately. You can use the "resample" command in MATLAB to adjust the sampling rates if needed.

## 3. How do I change the color or line style of the merged FFT spectrum graph?

To change the color or line style of the merged FFT spectrum graph, you can use the "plot" command with the desired color or line style as an input argument. For example, "plot(x, y, 'r--')" will plot the graph with a red dashed line. You can also use the "set" command to change the properties of the graph after it has been plotted.

## 4. How can I add labels to the x and y axes of the merged FFT spectrum graph?

You can add labels to the x and y axes of the merged FFT spectrum graph using the "xlabel" and "ylabel" commands in MATLAB. Simply use these commands with the desired label as an input argument. Additionally, you can use the "title" command to add a title to the graph.

## 5. Is there a way to save the merged FFT spectrum graph as an image file?

Yes, you can save the merged FFT spectrum graph as an image file using the "saveas" command in MATLAB. This command allows you to save the graph in various file formats, such as PNG, JPG, and PDF. You can also specify the desired file name and location for the saved image.