NETLOGO RANDOM NUMBER PATCH

Functions in R create new objects, they do not directly modify the ones given as arguments. The result/output of a function needs to be assigned to an object to be kept and re-used later in the model.

NETLOGO RANDOM NUMBER PATCH

For example, in the NLdist function, the argument agents takes one patch coordinates, the argument agents2 takes another patch coordinates, the argument world takes a worldMatrix or a worldArray object to indicate in which world agents and agents2 are located and the argument torus indicate that the world is wrapped. In NetLogoR, the function arguments indicate which world and/or agents ( i.e., patches and/or turtles) are involved in the function. # Create a world according to a given extent w1 <- createWorld( minPxcor = 0, maxPxcor = 10, minPycor = 0, maxPycor = 10) # Report the distance between the patch and the patch pDist <- NLdist( agents = cbind( pxcor = 0, pycor = 0), agents2 = cbind( pxcor = 1, pycor = 1), world = w1, torus = TRUE) In all cases of similar object types, we have implemented functions to convert between the types. agentMatrix is based on matrices and has no coordinate reference system, both of which make operations dramatically faster than with SpatialPointsDataFrame objects. The key difference in this case is for speed. agentMatrix is similar to SpatialPointsDataFrame from sp package, with a few differences. In worldMatrix and worldArray, integer coordinates are in the middle of the patch or cell, i.e., (0, 0) is in the middle of the patch in a worldMatrix that has 1m resolution and integer coordinates, whereas, (0, 0) would be at the edge of a cell in a Raster* that has 1 m resolution and integer coordinates. In worldMatrix and worldArray, (0, 0) is at the bottom left, like a mathematical graph, whereas it is in the top left in Raster* objects, as in geographic coordinates. Two important differences are the mapping of X and Y coordinates and whether integer locations are in the center or at the corners of integer coordinate systems. WorldMatrix and worldArray are similar to RasterLayer and RasterStack in the raster package. Patches coordinates are always integers but turtles coordinates can have decimals ( i.e., a turtle can be positioned anywhere on a patch). Turtles are defined by their coordinates xcor and ycor and data associated in agentMatrix objects. See help('worldMatrix-class') for more details on the patch coordinates system. Patches are represented as matrix objects with two columns pxcor and pycor, representing the spatial location ( i.e., coordinates) of the center of the patches. Patches cannot move whereas turtles can move.

There are two types of agents in NetLogoR: the patches and the turtles. It represents a two dimensional landscape, divided into a grid of square patches ( i.e., the matrix cells) of resolution 1.

In NetLogoR, the world is either a worldMatrix object (similar to a matrix) or a worldArray object (similar to an array which is a collection of matrices).

Netlogo random number