interval plot

From a series of intervals defined by start depth, end depth and type, create a interval plot.

example:
>> I=[10 12 1
13 15 2
17 22 1
23 28 1
29 30 2
31 34 2
35 36 1
36 38 2
38 40 1
43 46 1
46 47 2
48 49 2
50 53 1
54 57 1];
>> plotinterval(I,'v')