Question

matlab a(2:5,6:8)是什么意思

Answer 1

取数组a中 第2行到第5行，第6列到第8列的数据。

相当于从a中取出一个4 * 3 的矩阵。

你自己用一个例子就能理解了：

a = rand(7,9)
a(2:5,6:8)

 结果：

a =

    0.6991    0.8407    0.2511    0.9172    0.0540    0.0119    0.6020    0.2290    0.4427
    0.8909    0.2543    0.6160    0.2858    0.5308    0.3371    0.2630    0.9133    0.1067
    0.9593    0.8143    0.4733    0.7572    0.7792    0.1622    0.6541    0.1524    0.9619
    0.5472    0.2435    0.3517    0.7537    0.9340    0.7943    0.6892    0.8258    0.0046
    0.1386    0.9293    0.8308    0.3804    0.1299    0.3112    0.7482    0.5383    0.7749
    0.1493    0.3500    0.5853    0.5678    0.5688    0.5285    0.4505    0.9961    0.8173
    0.2575    0.1966    0.5497    0.0759    0.4694    0.1656    0.0838    0.0782    0.8687


ans =

    0.3371    0.2630    0.9133
    0.1622    0.6541    0.1524
    0.7943    0.6892    0.8258
    0.3112    0.7482    0.5383