Map and Table Calculation

AGGAVG( ) or ColumnAggregateAvg() function

Returns the average of an entire column, the averages per group, the weighted average of an entire column, or weighted averages per group.

Syntax

AGGAVG(ValueColumn)
AGGAVG(ValueColumn, Group)
AGGAVG(ValueColumn, , Weight)
AGGAVG(ValueColumn, Group, Weight)
ColumnAggregateAvg(ValueColumn)
ColumnAggregateAvg(ValueColumn, Group)
ColumnAggregateAvg(ValueColumn, , Weight)
ColumnAggregateAvg(ValueColumn, Group, Weight)

Input

Output

Notes:

• The AGGAVG and the ColumnAggregateAvg function are aliases of each other. These functions can be used both in a table window and in scripts.
• A 'group by' column can be specified when you perform an aggregation within one table. A 'group by' column must be specified when you perform an aggregation during a join.
• When no weight column is specified, all data gets the same weight value, i.e. weight 1.
• The function parameters refer to nothing else than column names. This means that within the brackets no other expressions can be used.
• Any undefined values in the input column are excluded from the calculation.

Tips:

• On the command line of a table window, you may also use the AVG function.
• When the definition symbol = is used, a dependent output column is created; when the assignment symbol := is used, the dependency link is immediately broken after the output column has been calculated.

Usable in

TabCalc

Examples

TabCalc example:

OutCol1 = AGGAVG(Area)

OutCol2 = AGGAVG(Area,Landuse)

OutCol3 = AGGAVG(Area,,Weights)

OutCol4 = AGGAVG(Area,Landuse,Weights)

• Column OutCol1 contains the average of the area of all parcels.
• Column OutCol2 contains the averages of parcel areas per land use class. E.g. for class Residential: (4000+3500+7500+5000) / 4 = 5000.
• Column OutCol3 contains the weighted average of the area of all parcels, i.e. (4000*2+3500*1+17500*4+7500*1+20000*?+12500*2+5000*1) / (2+1+4+1+2+1).
• Column OutCol4 contains the weighted averages of parcel areas per landuse class. E.g. for class Residential: (4000*2+3500*1+7500*1+5000*1) / (2+1+1+1) = 4800.

Advanced example

Use the following syntax to write output values from a table Parcel into in a new column of another existing table Landuse:

Landuse.AvgParSize = AGGAVG(Parcel.Area,Parcel.Landuse)

The average value of column Area in table Parcel grouped by Landuse, is written into column AvgParSize in table Landuse.

See also: