Hi Bob,
f is a vector with 1000 elements and consequently, so is the denominator. The dot allows matlab to divide each of the elements of the denominator into V, yieldiing a vector of length 1000 with the division done term-by-term.
In general to divide or multiply two vectors of equal length into each other term-by-term (either both are row vectors or both are column vectors), the dot is used:
c = a.*b or c = a./b
and if each vector is length n, so is the result. Here V is a scalar and not a vector, but in the special caseof a scalar, Matlab automatically does the element-by-element division anyway, using V as the numerator for every division.
When you start with independent variable x and want to create vector y = f(x), term-by-term using the dot is really common.
The same dot convention applies to matrices, where * indicates usual matrix multiplication and .* is term-by-term, and similar rules obtain for division, using / or \ and ./ or .\ For example
a = [1 2
3 4];
b = [5 6
7 8];
c = a*b
d = a.*b
c =
19 22
43 50
d =
5 12
21 32
