Empty Matrix: 1-by-0 error

In MATLAB I am trying to create a vector, A, which goes from 2*pi to 7*pi in increments of pi/4. My code is as follows:

   A = linspace((2*pi), (7*pi), (pi/4))

However when I push enter I get this message

 A =  Empty matrix: 1-by-0

How can I get around this error?

Answer 1

[Walter Roberson]

linspace's third argument is for the number of points to use. You used pi/4 which is 3.14.../4 which is less than 1.

You should use the colon operator

2*pi : pi/4 : 7*pi

Answer 2

[kowshik Thopalli]

help linspace()

   y = linspace(x1,x2,n)

generates n points. The spacing between the points is (x2-x1)/(n-1). so here x1= 2*pi, x2=7*pi . Since the difference is pi/4 n=21;

so

    A=linspace(2*pi,7*pi,21)

gives you what you want with the difference of pi/4