I would add one variable inside function

2019 3 10
2 个回答
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更新时间：2019 3 11
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I have x(t) and I would to create x(t+ta) by matlab code. For example
if I have x(t)= 2t+3 , I need to create x(t+ta)= 2t+2ta+3 and so on.
Please consider x(t)=5sin(2t+theta), and x(t+ta)=5sin(2t+2ta+theta) for your explaintion.
Thank you in advance.

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 采纳的回答

madhan ravi
madhan ravi 2019-3-10
编辑：madhan ravi 2019-3-10

0 个投票

Read about subs() :
syms a t theta
x(t)=5*sin(2*t+theta);
subs(x(t)*x(t+a),{t,a,theta},{1,2,3}) % t with value one ,a with 2 and theta 3 are example values

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Willim
Willim 2019-3-11
the answer still str , I need it as numbers to plot
madhan ravi
madhan ravi 2019-3-11
编辑：madhan ravi 2019-3-11
? What are the values of t , a & theta?
Willim
Willim 2019-3-11
I will intgrate the x(t)*x(t+ta)
so
int(x(t)*x(t+ta),t,0,pi)/pi
the answer will be
25*cos(ta)^2 - 25/2
I would substite ta by the array [1:1:10]
I have done this but the answer is not number , I tried str2num but does not help
Willim
Willim 2019-3-11
I think double(a) works to solve this problem

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KALYAN ACHARJYA
KALYAN ACHARJYA 2019-3-10
编辑：madhan ravi 2019-3-10

0 个投票

syms t ta theta
x(t)=5*sin(2*t+theta);
disp(x(t+ta))
Command Window
5*sin(2*t + 2*ta + theta)

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Willim
Willim 2019-3-10
Thank you but the result on disp cannot use to multiply with x(t). it gives
x(t)*disp(x(t+ta))
Error using sym/disp
Too many output arguments.
I need to have the result x(t)*x(t+ta).
after finding the x(t)*x(t+ta) which should be
25*sin(2*t + theta)*sin(2*t + 2*ta + theta)
How can I substitute t , theta , and ta values in
25*sin(2*t + theta)*sin(2*t + 2*ta + theta)
KALYAN ACHARJYA
KALYAN ACHARJYA 2019-3-10
编辑：KALYAN ACHARJYA 2019-3-10
Hello Faraj, you are doing wrong way, do the operation inside disp() only
Its giving the answer:
syms t ta theta
x(t)=5*sin(2*t+theta);
disp(x(t)*x(t+ta))
tttt.png

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