plotting tan(x) - basic student's question

I am new to matlab and have been trying to plot basic things.

I have sucessfully managed to plot sin(x) by doing the following:

x = -2*pi:pi/100:2*pi; y = sin(x); plot(x,y)

However, when I replace the sin(x) by tan(x), the plot does not come out right. I can't figure out why this is. On the other hand I have managed to plot tan(x) using ezplot...

Answer 1

[Mischa Kim]

Will, tan(x) has singularities (function goes to infinity) at pi/2 +/- n*pi. So when you plot over the range from -2*pi to +2*pi the data points just before and right after such a singularity will also be connected (by the default line), unless you tell MATLAB to ploint data points only (markers, essentially). For example,

 plot(x,y,'*')

Plus, you would also want to put a limit on your y-axis, something like

 ylim([-10 10])

Answer 2

[Wayne King]

tan(x) is periodic with period pi and "blows up" at odd multiples of pi/2 so why not just plot one period?

dx = 0.01;
x = -pi/2+dx:pi/100:pi/2-dx;
y = tan(x);
plot(x,y)

by increasing dx, you'll get a better visual because the value near +/- pi/2 grows in magnitude so quickly, the plot becomes dominated by the large negative and positive values,

dx = 0.1;
x = -pi/2+dx:pi/100:pi/2-dx;
y = tan(x);
plot(x,y)

Answer 3

[hai yang]

ezplot('tan(x)')

does the work very well

[Adil Rashid]

Greatest answer

Answer 4

[pulkit verma]

ezplot("tan(x)")