三个小技巧帮你提高MATLAB代码运行速度

    在进行大规模数据运算的时候，MATLAB的速度一直是一个让人诟病的问题。单是养成良好的编程习惯，

会让你在不经意间让你的代码运行效率提高数倍。

    1. 为循环中频繁存取的数组提前分配空间

    2. 以列为单位进行数据的存取

    3. 避免创建不必要的中间变量

1. Preallocate Arrays Before Accessing them Within Loops

---

   1:  N = 10e3;                                               

   2:   

   3:  x{1} = 1000； 

   4:  for k=2 : N 

   5:      x{k} = 1.05*x{k-1};  

   6:  end    

   7:    

   8:  Machine A = 0.14.9 sec

   1:  N = 10e3;

   2:  A = zeros{N,1};

   3:  for k = 2 ：N

   4:      x{k} = 1.05*x{k-1};

   5:  end

   6:   

   7:  Machine A = 0.00024 sec

---

3. Avoid Creating Unnecessary Variables

   1:  y = myfun(x);

   2:   

   3:  function y = myfun(x)

   4:  y = 1.2*x;

   5:   

   6:  Machine A = 0.0858 sec

   7:   

   8:  x = myfun_ip(x);

   9:   

  10:  function x = myfun_ip(x)

  11:  x = 1.2*x;

  12:   

  13:  Machine A = 0.0508 sec

转载于:https://www.cnblogs.com/bei_/archive/2011/01/16/1936930.html