Question

以下示例代码在-1,+1

大小的数组中随机分配N的值

N=100;    
D = sign(rand(1,N)-0.5).*ones(1,N);

如何控制数字分布中的偏差水平？

让我们举例说，只有20％的数组会有+1，其余的-1

Answer 1

如何在50％（0.5）的数字为负数的情况下进行分配？

N=100;    
D = sign(rand(1,N)-0.5).*ones(1,N);

如何在20％（0.2）的数字为负数的情况下进行分配？

N=100;    
D = sign(rand(1,N)-0.2).*ones(1,N);

如何在80％（0.8）的数字为负数的情况下进行分配？

Answer 2

如下所示

VAL = [-1 1]   % 2 values
P = .8          % probabbility of selecting first value
Ndraw = 100      % number of draws
R = rand(Ndraw,1) < P 
SEL = VAL(2 - R) % use as index into VAL

    SEL =

  Columns 1 through 19

     1    -1    -1     1    -1    -1     1    -1    -1    -1    -1    -1    -1    -1    -1    -1    -1    -1    -1

  Columns 20 through 38

    -1     1     1    -1    -1    -1     1    -1     1    -1    -1    -1    -1    -1    -1    -1    -1    -1    -1

  Columns 39 through 57

    -1    -1    -1    -1    -1    -1    -1    -1     1    -1     1    -1     1     1     1    -1    -1    -1    -1

  Columns 58 through 76

    -1    -1    -1    -1     1    -1    -1    -1    -1    -1     1    -1    -1    -1    -1    -1    -1     1     1

  Columns 77 through 95

    -1    -1     1    -1    -1     1    -1    -1    -1    -1     1    -1    -1    -1    -1     1    -1     1    -1

  Columns 96 through 100

    -1     1    -1    -1    -1

在Matlab中使用偏差分配有符号整数

2 个答案: