>> interpolates
year =
2011
pop_lagrange =
285.9566
pop_spline =
311.1920
year =
2018
pop_lagrange =
-616.7460
pop_spline =
298.2019
>> interpolatePL
nd =
5
>> interpolatePL
nd =
6
>> interpolatePL
nd =
8
>> interpolatePL2
>> interpolateCS
nd =
3
>> interpolateCS
nd =
4
>> interpolateCS
nd =
5
>> interpolateCS
nd =
7
>> interpolateCS
nd =
13
>>