1、mat文件的生成

(1)直接在Matlab中创建并保存矩阵数据

打开Matlab软件，点击左上角文件(File)，然后点击新建(new)，选择变量(Variable)，就新建了一个mat文件。

点击你新建的文件，即可打开一个编辑器，输入数据即可。

(2)保存单一矩阵数据

如图所示，输入数据，生成数组。最后输入save x1 x。该语句表示将敲入的数组x生成数据x1.mat文件。

(3)如果矩阵A.B都已赋值，现在需要将A,B矩阵保存成mat格式文件，执行如下命令：save mydata A B 就会把A B矩阵数据保存在mydata.dat文件中了。

2、mat文件的读取

在matlab中使用load语句读取mat文件。

(1)x1.mat文件和代码在同一个文件目录下。

load x1,y,a,b,c…;

(2)x1.mat文件和代码不在同一个文件目录下。

load ([‘目录\x1.mat’])

I have 25 images in a folder and I want to make a .mat file for a road-sign recognition system.

What are the steps for making a .mat file in Matlab?

解决方案

There may be a better approach for images but here is what I know. If you want to control what goes into the .mat file you can specify what variables in your workspace will be saved using the save command.

% MATLAB R2017a

X = rand(273,273);

Y = rand(273,273);

Z = rand(273,273);

save FileName X Y Z

This creates a file FileName.mat.

You can access the contents using the load command.

clear

load FileName

To save everything in the workspace to a .mat file, use the save command without specifying the variables to save (MATLAB will then save them all).

W = rand(273,273);

save FileName

See the linked documentation for more options and examples.

This requires you to loop through the images in the folder. A direct approach to this is directly loading the images using a loop over [filepath 'image' num2str(j) '.jpg'] with index j where filepath = 'C:\Users\user1\Folder\ImageFolder\'. This uses string concatenation and the num2str command.

If you need to change your current directory within the script,the cd function is useful.