How Cell Statistics works
By calculating cell statistics, a statistic for each location is calculated in which the value at each location on the output raster is a function of the input values at each location. Some details and examples of each statistic are provided below.
Mean
- Determines the average value of the inputs on a cell-by-cell basis.
- The output for Mean is always floating point.
- Example:
Majority
- Determines the value that occurs most frequently in the inputs on a cell-by-cell basis.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
- When there is more than one majority value for a cell location, the output for that location is NoData.
- If all input values for a cell location are the same, the output majority value for that location is the same as the input.
- A reasonable application should consist of at least three inputs. If only a single input is specified, the output will be a duplicate of the input.
- If there are only two inputs, any location where the values are different will be written as NoData. Since there are only two different values from which to choose, there is no majority value. If the values are the same, that value will be written to the output raster.
Maximum
- Determines the largest value of the inputs on a cell-by-cell basis.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Median
- Determines the median value of the inputs on a cell-by-cell basis.
- If the number of inputs is odd, the median value is calculated by ranking the values and selecting the middle value. If the number of inputs is even, the values will be ranked, and the middle two values will be averaged. This value will be truncated to an integer if all the input grids are of integer type.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Minimum
- Determines the smallest value of the inputs on a cell-by-cell basis.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Minority
- Determines the value that occurs least frequently in the inputs on a cell-by-cell basis.
- When there is more than one minority value for a cell location, the output for that location is NoData.
- If all input values for a cell location are the same, the output minority value for that location is the same as the input.
- A reasonable application should consist of at least three inputs. If only a single input is specified, the output will be a duplicate of the input.
- If there are only two inputs, any location where the values are different will be written as NoData. Since there are only two different values from which to choose, there is no minority value. If the values are the same, that value will be written to the output raster.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Range
- Determines the range of values in the inputs on a cell-by-cell basis.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Std
- Determines the standard deviation of the values in the inputs on a cell-by-cell basis.
- The output for Std is always floating point.
Sum
- Determines the sum of the values in the inputs on a cell-by-cell basis.
- If all the inputs are integer, the output is integer. If any of the inputs are floating point, the output is floating point.
Variety
- Determines the number of unique values in the inputs on a cell-by-cell basis.
- The output raster is always of integer type.
Related Topics
6/29/2011