matlab基本指令

基本命令

close all                                //关闭所有figure 命令打开的窗口，在命令窗口输入
clear all                                 //清除之前运行程序所存下的所有变量
 

size(mat)
    a = [1 2 3 ; 4 5 6 ]
    size(a) = [2 3]                                   //size(mat) = [rownum, colnum]

delete certain col in mtrix

A = [1 2 3 ; 4 5 6 ; 7 8 9];
A(:, 3) = [];

reshape array

z = reshape(preds(3,:,:),14,177);   //it will reduce demension of preds to 14X177

A = [1 2; 3 4]; permute(A,[2 1])    %%convert div 2 with div 1.
ans =
     1     3
     2     4

cat      %%merge matrix A ,B to a new matrix, extend div possibly
heatmap = cat(4,heatmap,hm)

矩阵连接

[s1 s2]    %%右侧连接
[s1; s2]   %%下侧连接

convert num to string

num2str

convert a cell struct to mat type

cell2mat

waitforbuttonpress: you can put it into for loop

subs = regexp(string, 'c', 'split');　　%%将string以'c'为分隔符分割为若干子串并保存至subs中

%%注意：subs是一个cell型数据，其每个元素是cell型的，只能display，不能直接进行字符串操作（如截取或者连接），这时需要字符转换：如，s1=char(subs(1))

画图

hist(x);   %%show the 2-D array x' hist 

mesh(Z)     %%plot 3D figure, where Z is f(m ,n).

I = imgaussfilt(I, 'FilterSize', 11);   %%I is image, 11 is size of filter size

连接图

plot(y)  //默认x坐标为正整数
plot(x, y) 
hold on     //表示下次画图基于本图

散点图

scatter(x, y)  //以x，y为横纵坐标画散点
scatter(x, y, ‘filled’)      也可以改为 ‘rx’     //即以不同元素表示散点