GNU Octave

Time for action – using the cos function

1. In order to calculate cosine of a number, say π, we simply type:

   pi is the input argument, cos is the Octave function and -1 is the output from cos. When we use a function we often say that we call that function

   octave:1>cos(pi)
   
   ans = -1
   

2. What if we use a vector as input? Well, why not just try. We know how to instantiate a vector:

   octave:2> x = [0:pi/2:2*pi]
   
   ans =
     0.0000    1.5708    3.1416    4.7124    6.2832    
   

   Cosine of x is then:

   octave:3>cos(x)
   
   ans =
     1.0000e+000   6.1230e-017   -1.0000e+000   -1.8369e-016   1.0000e+000
   

   that is, Octave calculates the cosine of each element in the vector.

3. In Command 2, we created a row vector, and the result of Command 3 is therefore also a row vector. If we use a column vector as input ...