Clip Raster By Polygon

This code clips a raster data to a polygon and calculates some statistics. Current operations are:
- Aggregate By Area: sum all the pixels within the polygon. Values are multiplied by the overlapping area of the pixel and the polygon.
- Average By Area: averages all the pixels within the polygon. The average is a weighted average based on the overlapping area of the pixel and the polygon
- aggregate: Sum of all the pixels that area within the polygon, even if partially.
- average: averages all the pixels within the area, even if partially.
- Majority: Returns the most frequently occuring value among all the pixels within polygon (even if partially). It uses "mode" function of matlab.