1. sort by second columns then first column in descending order

In [5]:
a=[1 4 5
5 2 1
2 2 4]

Out[5]:
3x3 Array{Int64,2}:
1  4  5
5  2  1
2  2  4
In [11]:
sortrows(a, by=x->(x[2],x[1]),rev=true)

Out[11]:
3x3 Array{Int64,2}:
1  4  5
5  2  1
2  2  4

2. submatrix

In [14]:
b=rand(5,5)

Out[14]:
5x5 Array{Float64,2}:
0.797137  0.270514  0.917754  0.545996  0.285527
0.973702  0.748511  0.402551  0.848309  0.951121
0.725661  0.698808  0.93761   0.422556  0.982648
0.041232  0.922575  0.459169  0.931272  0.435496
0.411451  0.333348  0.35009   0.421053  0.098248
In [19]:
rows=[1,3]
columns=[3:size(b,2)]
b[rows,columns]

Out[19]:
2x3 Array{Float64,2}:
0.917754  0.545996  0.285527
0.93761   0.422556  0.982648

3. list functions in a module (or check a function)

In [8]:
using PedModule

In [9]:
names(PedModule, true)

Out[9]:
12-element Array{Symbol,1}:
:PedModule
:fillMap!
:PedNode
:AInverse
:genoSet!
:code!
:Pedigree
:calcInbreeding!
:mkPed
:eval
:calcAddRel!
:getIDs         
In [10]:
methods(PedModule.code!)

Out[10]:
1 method for generic function code!:

3. find function (similar to which function in R)

In [1]:
a=[3,7,9]
find(x->x>4,a)

Out[1]:
2-element Array{Int64,1}:
2
3