Turtle and Observer Command
sum-of-turtles-with `[condition] [list of commands]` Reports the total value of `[list of commands]` when run over the turtles that satisfy the `condition`. If there are no turtles in which the `condition` is true, returns 0. 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-turtles-with [color = red] [age]` returns the sum of the ages of all the red turtles. Related commands: sum-of-turtles