time shifting
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i want the program to advance or delay the signal... by taking input from user whether to advance or delay & by what number?.... please use switch statement?.... any signal like-ramp,step,exponential in it i am using subplot to plot the original signal & shifted version of the signal..
i have a program something like this--
*clear all
close all
clc
disp('given function is')
x=(-10:10);
for i=1:1:21
if(x(i)>0)
y(i)=exp(x(i));
else
y(i)=0;
end
end
subplot(1,2,1)
stem(x,y)
disp('enter whether to advance or delay')
s=input('1>advance\n 2>Delay')
n=input('enter the no of step by which signal is to be shifted')
switch(s)
case 1
[
for i=1+n:1:21+n
if(x(i)>0)
y(i)=1;
else
y(i)=0;
end
]
case 2
[
for i=1-n:1:21-n
if(x(i)>0)
y(i)=1;
else
y(i)=0;
end
]
subplot(1,2,2)
stem(x,y)
but when i run the program it gives error in the 'for' command in case 1.
3 个评论
Paulo Silva
2011-2-20
What kind of signal and why use switch statement?
usually switch statements are for more complex problems.
Matt Tearle
2011-2-20
Can you please explain in more detail what you're trying to do? Do you have a time base vector t and a signal y(t) and you want the user to input a dt... and then do... what with it exactly?
ap singh
2011-2-21
采纳的回答
Jan
2011-2-21
Omit the square brackets around the case blocks and close the SWITCH and IF blocks with an END.
switch(s)
case 1
for i=1+n:1:21+n
if(x(i)>0)
y(i)=1;
else
y(i)=0;
end
end
case 2
for i=1-n:1:21-n
if(x(i)>0)
y(i)=1;
else
y(i)=0;
end
end
end
更多回答（6 个）
For detailed post and complete code visit: https://www.swebllc.com/time-shifting-in-matlab-code-output/
Walter Roberson
2011-2-21
0 个投票
You cannot have an 'if' statement inside of [] . But you don't need to mark the beginning and end of the code for an individual case: all code is executed until the next 'case' or unmatched 'end'.
Matt Tearle
2011-2-21
On top of the syntax issues Walter and Jan point out...
1. Why use switch? You could easily use a simple if/|else|. But why not just flip the sign of the offset. Something like n = sign(1.5-s)*n
2. You can make the unshifted signal in a couple of lines:
y = exp(x);
y(x<=0) = 0;
3. What you have in the switches will cause an error because it will try to reference x(22) (or higher), but x only has 21 elements. What are you trying to do here? I would have thought that what you want mathematically is y(x+dx). In which case you could repeat the above lines with a shifted x:
x2 = x + dx;
y = exp(x2);
y(x2<=0) = 0;
Also, what you have there sets y to just 0 or 1, rather than 0 or exp(x). Was that what you intended?
Saurabh
2024-9-15
0 个投票
clear all
close all
clc
disp('given function is')
x=(-10:10);
for i=1:1:21
if(x(i)>0)
y(i)=exp(x(i));
else
y(i)=0;
end
end
subplot(1,2,1)
stem(x,y)
disp('Enter whether to advance or delay')
s=input('1>advance\n 2>Delay=\n')
n=input('enter the no of step by which signal is to be shifted=')
switch(s)
case 1
for i=1+n:1:21+n
if(x(i)>0)
y(i)=exp(x(i));
else
y(i+n)=0;
end
end
case 2
for i=1-n:1:21-n
if(x(i)>0)
y(i)=exp(x(i));
else
y(i-n)=0;
end
end
end
subplot(1,2,2)
stem(x,y)
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