How to shorten a signal (in terms of time)?

[electroabdo]

Hello,

I have a signal with time from 0 until 275. How can i only take the first 260 of it? like from 0 to 260 and ignoring the other parts.

thanks in advance

 

[betwixt]

Re: shortening of signal

What is the nature of the signal?
The solution to your problem depends on the size of the time units and at what voltage/current they are presented as. For example, is each time unit one day or 1uS and is it a logic level signal or something else?

Brian.

 

[electroabdo]

Re: shortening of signal

What is the nature of the signal?
The solution to your problem depends on the size of the time units and at what voltage/current they are presented as. For example, is each time unit one day or 1uS and is it a logic level signal or something else?

Brian.

Ok, i written in matlab these lines:

oneperiod=[zeros(1,20) ones(1,20)];
sixperiod=repmat(oneperiod,[1 6]);
stim=[sixperiod,zeros(1,20)]

so now we have 260 samples.. and i convolved this "stim" function with a continuous signal which has different values, this signal has 16 values (from 0 to 16) so the result is 260+16-1=275 by the convolution rule. The results of course is another continuous signal ( and not signal with 1s and 0s) the time unit is in 's'. Anyway in matlab function i have a matrix of 1x275 dimensions.

 

[betwixt]

Re: shortening of signal

Over to someone else.... I haven't got Matlab...

Brian.

 

[electroabdo]

Re: shortening of signal

Should I post this in another forum? or?

 

[opt]

Re: shortening of signal

260 points convoluted with 16 points kernel get the 260+16-1=275 point result. what's your reason to discard other points for keeping the same size of input?

 

[electroabdo]

Re: shortening of signal

260 points convoluted with 16 points kernel get the 260+16-1=275 point result. what's your reason to discard other points for keeping the same size of input?

because i need to correlate this signal with another one of 260 points. The dimensions must agree.

 

[opt]

Re: shortening of signal

correlation is some like convolution, is there requirement that the two sequence in convolution must be equal size?

 

[electroabdo]

Re: shortening of signal

correlation is some like convolution, is there requirement that the two sequence in convolution must be equal size?

for convolution it's not necessary to have parameters of equal sizes but for correlation it is!