Question

我有一个1s和0s的二进制向量。我想找到一个函数范围/数字岛1。例如：x = 0001111001111111000110 ... 我需要这样的答案：4-7（或4 5 6 7），10-16,20-21 ...... 谢谢你的帮助！

Answer 1

在原始数组的两端添加零可保证偶数个转换（从0到1开始，从1到0结束）然后它基本上是diff的问题并且微调输出

x = [0 0 0 1 1 1 1 0 0 1 1 1 1 1 1 1 0 0 0 1 1 0];
% how to make that out from a string  xx="0001111001111111000110" is left
% as an exercise
y = [0 x 0];        %  make sure x="11"; has proper amount of transitions
R = 1:length(y)-1;  %  make an array of indices [1 2 3 4 5 ... end-1]
F = R(y(2:end) != y(1:end-1));          % finds the positions [4,8,10,17,20,22]
start_pos = F(1:2:end-1);  % gets 4,10,20
end_pos = F(2:2:end)-1;    % gets 7,16,21 adjusted

免责声明：未经测试。

Answer 2

Aki解决方案的变体（未经过大量测试）：

x = [0 0 0 1 1 1 1 0 0 1 1 1 1 1 1 1 0 0 0 1 1 0];
dx = diff([0, x, 0]);
start_pos = find(dx == 1);
end_pos = find(dx == -1) - 1;

Matlab：如何查找范围？

2 个答案: