How to transform function in MatLab? Shift, Scale etc.

34 次查看（过去 30 天）
ha9981
ha9981 2012-9-23
评论： Preetha Thanunathan 2020-4-7
If I have a function as follows:
syms x1;
syms t;
x1 = exp(t)* Heaviside(2*t);
How do I do define x2 = x1(t-2) so I can plot it. I would rather not have to redefine the entire function doing the work myself each time I want to do a transformation. Is there a way of achieving this?
  1 个评论
Preetha Thanunathan
Preetha Thanunathan 2020-4-7
I have a function f(x) whose range is the interval [0, 1], and I need to shift it and stretch it so that the range is now the interval [a, b]. Find a function g(x) (defined in terms of f(x)) so that g(x) has an range [a, b].
In Matlab, the rand command produces a random number between 0 and 1, under the uniform distribution; that's different from the normal distribution. The graph of the uniform probability distribution is a horizontal line. The graph of the normal distribution is the bell curve.
I need a program that will accept input values a and b, a < b, and will output a random number between a and b, You'll do this by shifting and stretching the rand function. Notice that in Matlab the rand function doesn't take an input. You just type rand and hit enter, and the program will spit out a random number between 0 and 1.
can anyone answer this question

请先登录，再进行评论。

请先登录，再回答此问题。

回答（3 个）

ha9981
ha9981 2012-9-23
http://www.mathworks.com/help/symbolic/subs.html
I think I found it. Appears to work.
x3 = subs(x1, t, t-2)
Is this a correct and reliable way?
Wayne King
Wayne King 2012-9-23
编辑：Wayne King 2012-9-23
I don't know of a shift operator for symbolic functions.
syms t
tprime = t-2;
x1 = exp(t)*heaviside(2*t);
x2 = exp(tprime)*heaviside(2*tprime);
Or just:
x2 = exp(t-2)*heaviside(2*(t-2));
  3 个评论
显示 1更早的评论
ha9981
ha9981 2012-9-23
You fixed it now. It said xprime before so it wasn't going to work.

请先登录，再进行评论。

Azzi Abdelmalek
Azzi Abdelmalek 2012-9-23
编辑：Azzi Abdelmalek 2012-9-23
syms t x
x1 = exp(t)* heaviside(2*t);
t=0:.1:10
if you want to plot |x1(t-2)| then
y=eval(x1)
t=t+2 % not t=t-2 because it's a delay
close;plot(t,y)
set(gca,'xlim',[0 max(t)])

类别

在 Help Center 和 File Exchange 中查找有关 Mathematics 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by