A function f can be broadcast over all elements of an array (or matrix) by using the dot notation f.(matrix); for example:

arr = [1.0, 2.0, 3.0] 
sin.(arr) #> 
3-element Array{Float64,1}:
#  0.8414709848078965 
#  0.9092974268256817 
#  0.1411200080598672  

Here is another example:

f(x,y) = x + 7y 
f.(pi, arr)  
#> 3-element Array{Float64,1}: 
# 10.141592653589793 
# 17.141592653589793 
# 24.141592653589793 

Broadcasting is very useful in Julia to write compact expressions with arrays and matrices.