Any other ways to program tan(x) between [-3*pi/2 to 3*pi/2])?

Hello!

I write down the code for the tan(x) between [-3*pi/2 to 3*pi/2]), but I want to reduce it, or doing it in another way. Any ideas?

x1=-(3*pi/2)+0.01:0.01:-(pi/2)-0.01;
plot(x1,tan(x1),'r','linewidth',2.5)
hold on
x2=-(pi/2)+0.01:0.01:(pi/2)-0.01;
plot(x2,tan(x2),'r','linewidth',2.5)
x3=(pi/2)+0.01:0.01:(3*pi/2)-0.01;
plot(x3,tan(x3),'r','linewidth',2.5)
hold off

Answer 1

[Image Analyst]

x = -3*pi/2 + .1 : 0.1 : 3*pi/2 - 0.1;
y = tan(x);
plot(x, tan(x), 'r','linewidth',2);
grid on;

[Mohammed Sayan]

Thanks but I know that! The problem is tan(x) doesn't converge to [-3*pi/2 -pi/2 pi/2 3*pi/2]...That was my reason to program it like that!

[Image Analyst]

It works. I don't know what you want to do. Do you just want to display it but not have the axes go from -inf to +inf? If so, just use ylim() to set it to whatever you want. MATLAB does handle infinity so you just need to define exactly what you want to plot.

x = -3*pi/2 : 0.1 : 3*pi/2;
y = tan(x);
plot(x, y, 'r','linewidth',2);
ylim([-10, 10]);
grid on;

[Mohammed Sayan]

Now it is correct, What about if I want to remove the vertical lines??

[Image Analyst]

You can cover them up with black lines using the line() function, or you can set values more than 10 or 1000 or whatever to nan:

x = -3*pi/2 : 0.01 : 3*pi/2;
y = tan(x);
maxYtoPlot = 10;
minYtoPlot = -10;
y(y > maxYtoPlot) = nan;
y(y < minYtoPlot) = nan;
plot(x, y, 'r','linewidth',2);
ylim([minYtoPlot, maxYtoPlot])
grid on;

[Mohammed Sayan]

Good JOB!

Answer 2

[Azzi Abdelmalek]

x=-3*pi/2+0.01:0.01:-(pi/2)-0.01
y=tan(x)
y=[y nan y nan y]
x=linspace(x(1),pi/2-0.01,numel(y))
plot(x,y)

[Mohammed Sayan]

I am sorry to say it is not correct because the tan(x) must pass through [-pi 0 and pi] which yours doesn't!!!

[Azzi Abdelmalek]

Look at x, you will see that x takes values near 0, if you want to be more closer to 0, you have to choose a very small sample time

[Mohammed Sayan]

Thanks, I need to try it to see!