Programming
Basic Programming
So, you have decided to write a program that will calculate y=x^2 for a
sequence of x's.
Programming in Matlab is actually very simple for someone with a C
background. To program, you just write C-code, minus the declarations,
pre-processing, memory allocation (done automatically in Matlab), and
other distracting extra junk. Thus, in order to obtain the (x,y) pairs
mentioned above, you may try something like the following:
for i=1:10 %equivalent to for(i=1; i<=10; i++)
x(i)=i;
y(i)=x(i)^2
Notice that the % sign is used to comment out the remainder of the line.
While the for-loop above works much like in C (as do if-else-then
statements, and most of the other conditional logic), this approach does
not utilize what Matlab is best at - matrix manipulation. It would be
much easier to just represent x as a vector or matrix, and perform matrix
operations on it to obtain y. This can be accomplished by the following
simpler code:
x=1:10; %x is a vector with 10 elements: [1 2 3 4 5 6 7 8 9 10]
y=x.*x; %the dot means element-by element multiplication (dot product)
We can check that y is what we expected by simply typing in "y" in the
command window after running the program. The output should resemble
y=[1 4 9 16 25 36 49 64 81 100]
This result can now be plotted.