MATLAB|Read a file and store its different contents as different matrices

path='D:\vitual_viewpoint\balloons\cam_param_balloons.txt';

LMat_In_ref = dlmread(path,'',[pbnum_L*10+1 0 pbnum_L*10+3 2]);

path is the file path. The
middle '' means skipping spaces. The
following matrix is ​​the area to be stored starting from 0 [mn m1 n1]

M = dlmread(filename) %%%将ASCII分隔的数字数据文件读入矩阵M中。dlmread函数从文件中检测分隔符，并将重复的空格视为单个分隔符。

M = dlmread(filename,delimiter)%%%使用指定的分隔符从文件中读取数据，并将重复的分隔符字符视为单独的分隔符。

M = dlmread(filename,delimiter,R1,C1)%%%从R1行到C1列范围内读取

M = dlmread(filename,delimiter,[R1 C1 R2 C2])%%%上述

This article is very detailed!