GNU Octave

Time for action – instantiating a structure

1. To set the projectile mass, we can use:

   octave:32>projectile.mass = 10.1
   
   projectile =
   {
   mass = 10.100
   }
   

2. The velocity field is set in a similar fashion:

   octave:33>projectile.velocity = [1 0 0]
   
   projectile =
   {
   mass = 10.100
   velocity =
      0    0   
   }
   

3. We can also set the text field as usual:

   octave:34>projectile.type = "Cannonball"
   
   projectile =
   {
   mass = 10.100
   velocity =
   	1    0    0
   type = Cannonball 
   }
   

and so on for position and whatever else could be relevant.

What just happened?

Command 32 instantiates a structure variable with the name projectile by assigning a field named mass the value 10.100. At this point, the structure variable only contains this one field.

In Commands 33 and 34, we then add two new fields to ...