Turtle and Observer Command

sum-of-frogs-with [condition]
[list of commands]

Reports the total value of [list of commands] when run over the
turtles of breed frogs that satisfy condition. If there are no frogs in which condition is true, 0 is
returned. Note: This command can
also be executed by patches, for example within an ask-patches statement.

Note: When a turtle calls the command, it is not included as part of the calculation.

Examples:
sum-of-frogs-with [color = green] [age] returns the sum of all
of the ages of the green frogs.

Related commands:
sum-of-frogs