First time user of Matlab having issues trying to plot: y=sin x/x on an interval -30<x<30.

Below is the code below I created and when I enter it at the >> prompt in the Command window, nothing happens and no graph appears.

x=linespace(-30,30,10001);
y=sin(x)./x;
plot(x,y,'-');
axis([-30 30-1 1])
xlabel('x')
ylabel('y')
title('Fred Smith')

1-is the code correct and do I need to create an m-file ->enter the code then save -> then type in the file name at the >> prompt for it to run. I know this is very basic but I was given the assignment without ever using Matlab and I have been researching this for hours. Thanks

Answer 1

[Mischa Kim]

Use

 x = linspace(-30,30,10001);

and

 axis([-30 30 -1 1])

instead. Otherwise the code looks fine. That is, copy-paste the whole thing and execute in the MATLAB command window. Alternatively, you can put the code into a script or a function and follow the steps you outlined above.

[Image Analyst]

Though unless you have some super huge screen, you might use 1000 instead of 100001 because you'll never fit that many pixels on a normal screen - it will have to subsample. By the way, there is a sinc() function to do the sin(x)/x operation. Also be aware that there is a sind() function if your input is in degrees instead of radians. And, if you want, you can adjust font size like this:

fontSize = 25;
xlabel('x', 'FontSize', fontSize)
ylabel('y', 'FontSize', fontSize)
title('Fred Smith', 'FontSize', fontSize)

[James]

Made the corrections and re ran the code and it worked like a charm. Thanks

Answer 2

[VISHNU VARDHAN REDDY B]

fontSize = 25;

xlabel('x', 'FontSize', fontSize)

ylabel('y', 'FontSize', fontSize)

title('Fred Smith', 'FontSize', fontSize)