Turtle and Observer Command

sum-of-patches-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 patches in which `condition` is true, it reports 0. Note: This command can also be executed by patches, for example within an `ask-patches` statement.

Examples:
`sum-of-patches-with [pc = green or pc = blue] [density]` returns the sum of the densities of all patches which are blue or green.

Related commands:
sum-of-patches