Modifying Duration, Amplitude and Periods of Rectangular Signal in Matlab Easily

For some time now I have a problem with generating a rectangular signal in matlab - but in such a way that it is easy to change its duration, amplitude and number of displayed periods.
For example, for sine there was no problem:

y=A*sin(2*w*m);

Pomerania anyone?

You can use either the sum of the sine with some of its harmonics or if possible a properly written function http://pl.wikipedia.org/wiki/Heaviside_step_function%27a

A sine with few harmonics ? How can I transfer this to matlab? I can transfer the functions you provided on average - at least in ways known to me (zeros, ones).

I was just using the sine function. I don't remember the exact syntax but something like if (sin(2*w*m))>=0 then y=1 else y=-1.

In this example of mine with the sine of the notation:

A - amplitude
m=T:0.0001:TE;
T - starting time
TE - end time
w=number_periods*pi/TE;

so I guess I won't do it like you said :/

I wanted to do this:

t=-5:0.0001:5;
pulse = A*rectpulse(t,3);
plot(t,pulse)

but in this case I can't give myself how many periods there will be - there is always one and it's in the middle of the axis :/

Why not? You have already set all parameters of the waveform in the sine signal. The if condition only changes the shape. The only downside of the solution is that "1" is longer than "-1" by 2 samples.

And can you write it all down somehow - I don't think I've ever done it like that and therefore I don't know how to "bite it"?

Not to mislead you. I was dealing with matlab about 5 years ago and I don't remember the syntax. Build an array with the time and values of the sine function since at specified w, then overwrite it with a condition to the same array.
Assuming you already have y=sin... something like this:
for k=1:length(y),
if (y(k) >=0) y(k)=A,
else y(k)=-1*A,
end
end

Try it and then fix what doesn't work

-------------------

I checked on Octave. Works

It will be somehow different than before - Matlab is not C++

I checked the code above on Octave - it went and generated a nice rectangle.

It's not possible - it throws errors in elsa for me :/

Paste all the code you used

for example:
t=0:0.01:6;
w=5 * pi / 6.0;
y=sin (2 * w * t);
for k=1:length(y),
if (y(k) >=0) y(k)=1,
else y(k)=-1,
end
end

fences)
hold on

And it works

It actually works - in elsa I gave ; instead ,...
But how to determine the length of the period here?

Actually, there's something about the scale because it's all times 100 :/

What do you mean by period length?
You set the time range at the beginning and then when counting "w" you specify the number of periods, so the length of the period is TE/n.

Yes, that's right - but I'm talking about the scale - I don't know why there are such large values since:

t=0:0.01:6;

then max should be 6 in my opinion - and here 600 is ...

Are you displaying it as I wrote? (plot (y)) If so, then it should be, because the x-axis is the sample number in the table, and since there are 601 of them, these are the x-scale values. Try plot(t,y)...

That's right - I don't know why I didn't try it myself. anyway thanks - now everything is as I wanted . I generated the sawtooth signal myself so I got what I wanted - thanks .

Hunter-Killer wrote:

A sine with few harmonics ? How can I transfer this to matlab? I can transfer the functions you provided on average - at least in ways known to me (zeros, ones).

In Matlab, a function named heaviside , properly combining the signal from these functions and "looping" it so that it is periodic, you will get a square wave.

Sometimes gentlemen, it's worth using the ''symulink'' overlay And if something doesn't work out or comes out poorly, give up electronics and electrical engineering in mat. After all, there are intuitive programs like Tcad.

Just what I do works well in matlab - I had a problem with this rectangle only and with one more thing I have a problem...

Is it possible to make a script in matlab such as in the picture below:



I just have a few graphs on one to make a comparison, but the most is happening around, for example, the value of 8 on the Y scale and I would like it to be "denser" with values such as changes every 0.1 and then larger changes - it can be done somehow and it's so that matlab itself would set it (automatically) and I wouldn't have to set every graph myself.
I thought it was a logarithmic scale in matlab and after the case, but calling semilogy does not do the job .... some ideas (actually not this topic, but related ).

Maybe it's enough just to enlarge (zoom) the graph window?

If I zoom in then I can't see the whole graph...

Maybe something with the axis min and max to combine and hold on to show several graphs, matlab itself will determine the scale?

I'm not very good with matlab but sometimes there was no such thing as "square" to generate a square wave??

Yes, it is to be generated, but then there is a problem with determining the period of the signal - in any case, "kuuczoo" proposed the most suitable solution for me, so I think the topic is already closed - thanks to all those who helped.