信号移位时间 [英] Shifting time of a signal

问题描述

考虑信号x = t.*(2*t + 4)

如果我想对信号进行时移-比如说2个时间值向右-可以做类似的事情

In case I want to time shift the signal -let's say 2 time-values to the right- is it possible to do something like

x = x(t-2)

为了移动所有值? 我偶然发现了circshift，但没有发现我的情况有用

In order to shift all the values ? I stumbled across circshift but I didn't find any use for my case

编辑:我正在寻找一种适用于每种信号的解决方案，例如，如果我反射x(或对其进行任何处理)并将其存储在Y上，我该如何解决?时移Y?

I'm searching for a solution where it will work for every signal, as an example if I reflect x (or do anything on it) and store it on Y, how should I time shift Y?

推荐答案

您可以将信号定义为函数，以便随心所欲地对其进行移位.

You can define the signal as a function, so that you can then shift it as you wish.

例如，

x = @(t) t.*(2*t + 4); % A function x(t)
y = @(t) x(-t); % A reflected version of the function
z = @(t,a) x(t-a); % A delayed version of the function 

t = -5:0.01:5; % Sampling instants

X = x(t); % A vector of samples of the original signal
Y = x(t-2); % A vector of samples of the delayed signal

请注意，如果要定义可以反映和移动任何功能的运算符，则可以例如写

Note that if you want to define operators that can reflect and shift any function, you can e.g. write

Rop = @(s,t) s(-t);
Sop = @(s,a,t) s(t-a);

您可以在x信号上将它们用作

And you can use them on the x signal as

Rop(x,[-2 -1 0 1 2]) % Calculates x([2 1 0 -1 -2])
Sop(x,5,[1 2 3 4 5]) % Calculates x([-4 -3 -2 -1 0])

如果您想将平移和反射结合起来，可以这样做:

If you want to combine shifting and reflection, you can do like this:

Rop(@(t) Sop(x,2,t),[1 2 3 4 5]) % First shifts x by 2, then reflects
Sop(@(t) Rop(x,t),2,[1 2 3 4 5]) % First reflects x, and then shifts by 2

如果运行上面的代码，您将看到反射和移位不是可交换的，因为生成的向量是不同的.

If you run the above code you will see that reflection and shift are not commutative because the resulting vectors are different.

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