Significance of the (.) operator

When I have to integrate a function of x such as : @(x)(normpdf(x).*payoff(s(x)))

Why do I need to use the (.) operator before the (*) operator?

Can someone please help?

I am using the R2011a version

Answer 1

[SRI]

HI refer from this link this may will give a clear idea for you

http://dali.feld.cvut.cz/ucebna/matlab/techdoc/ref/arithmeticoperators.html

Answer 2

[David Sanchez]

The means the product is performed element-wise in both matrices on wither side of the product sign:

Example:

a=[1 2 3];
b=[2 3 4];
c=a.*b
c =

     2     6    12

You would not need a dot this case:

d=2*a

d =

     2     4     6

the multiplication factor is a scalar and it will apply to every element of a.