在指定数字范围之间创建一个随机的X-Y矩阵.这里发生了什么事?

问题描述

我正在学习范德比尔特大学(Vanderbilt University)的一门有关Matlab基础知识的在线课程(关于使用MATLAB进行计算机编程入门的Coursera MOOC，讲师:Mike Fitzpatrick).在课程中，教授创建了一个名为myRand的自定义函数，以在设定的数字间隔内生成一个3×4矩阵.

I am following an online course from Vanderbilt University on the basics of Matlab (Coursera MOOC on introductory computer programming with MATLAB, Instructor: Mike Fitzpatrick). In the course the professor creates a custom function called myRand to produce a 3-by-4 matrix within a set interval of numbers.

我知道Matlab内置了相同的功能，但教授从头开始创建了自己的函数，以告诉我们内置函数的幕后情况.

I know that an identical function is built into Matlab but the professor created his own from scratch to teach us what is going on behind the scenes of the built-in functions.

% Produce a 3-by-4 matrix between between the input low and high
function a = myRand(low,high)
a = low + rand(3,4) * (high-low);
end

'>>test = myRand(2,10)

test =

    5.1378    7.6484    2.3694    7.5586
    7.2438    2.2547    2.7771    4.5368
    3.3695    4.2154    8.5877    9.6018

我了解是因为rand()会产生0-1的随机数； "low"将设置下限(low + rand)，这是有道理的.但是，我不知道如何设置上限. (高-低)"运算是高和低之间的差异.在"myRand"的任何地方都没有明确地设置"High"的规范.

I understand because rand() produces random numbers from 0-1; it makes sense that 'low' will set the lower limit (low+rand). However I do not know how upper limit is set. The operation '(high-low)' is the difference between the high and low. and no where in 'myRand' is there a specification to set 'High' explicitly.

有人可以帮助我理解这一点吗?

Can someone help me understand this?

推荐答案

说明示例:-

假设 low = 2 和 high = 5 .
现在您已经知道 rand 生成的值始终在 0 和 1 之间.

Suppose that low = 2 and high = 5.
Now as you already know that the values generated by rand are always between 0 and 1.

如果生成的值为 0 ，则
a = low + value *(high-low); 表示 a = 2 + 0 *(5-2) = 2

If the generated value is 0 then
a = low + value *(high-low); means that a = 2 + 0 *(5-2) = 2

，并且当生成的值为 1 时，
a = low + value *(high-low); 表示 a = 2 + 1 *(5-2) = 5

and when the generated value is 1 then
a = low + value *(high-low); means that a = 2 + 1 *(5-2) = 5

这意味着在 0和1 之间生成的任何值都会在 2和5
之间给出 a .如果 values ∈ (0,1) ，则表示 a ∈ (2,5)

It means that any value generated in between 0 and 1 will give a in between 2 and 5
i.e. if values ∈ (0,1) then it means that a ∈ (2,5)

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