Octave Example 1: Getting Started

Al Fischer

First Approximation: Octave is a calculator

In a basic sense, the Jupyter interface is just a glorified calculator.



In [21]:

    
### add 2 + 3

2 + 3









    



ans =  5



In [23]:

    
### divide

3 / 4









    



ans =  0.75000



In [26]:

    
### natural log

log(10)
log10(10)









    



ans =  2.3026
ans =  1



In [30]:

    
### what about trig?

cos(pi)
sin(pi/2)









    



ans = -1
ans =  1

PAUSE: Find the sine of 45 degrees



In [50]:

    
a = [1 2 3 4];



In [51]:

    
a









    



a =

   1   2   3   4



In [52]:

    
a + 2









    



ans =

   3   4   5   6



In [54]:

    
B = [1 2 3 4; 6 8 10 12]









    



B =

    1    2    3    4
    6    8   10   12



In [55]:

    
C = B / 2









    



C =

   0.50000   1.00000   1.50000   2.00000
   3.00000   4.00000   5.00000   6.00000



In [56]:

    
a * B









    



error: operator *: nonconformant arguments (op1 is 1x4, op2 is 2x4)



In [57]:

    
a .* B









    



ans =

    1    4    9   16
    6   16   30   48



In [58]:

    
D = a .* B









    



D =

    1    4    9   16
    6   16   30   48



In [62]:

    
D(1, 4)









    



ans =  16



In [43]:

    
x = [0:0.1:4*pi];
y = [sin(x); cos(x)];

plot(x, y);
xlabel ("x");
ylabel ("y");
legend("sin(x)", "cos(x)")