```matlab
r=randn;
```
```matlab
r=randn(2,3);
```
```matlab
mean=5;
std_dev=2;
r=mean+std_devrandn;
```
```matlab
mean=5;
std_dev=2;
r=mean+std_devrandn(2,3);
```
```matlab
random_numbers=zeros(1,1000);%初始化一个1x1000的数组，用于存储随机数
fori=1:1000
random_numbers(i)=randn;
end
```
