问题
I am working with NetLogo code written with somebody else (freely available to public). I try to understand how the procedure of turtle moving is elaborated and, most important - how make it computationally faster without loosing sensitivity of turtle movement in relation to worlds' patches?
I suppose that the most of the calculation time is used to calculate the distance of each step of turtle movement - I would like to measure only one variable from patch of turtle's origins to last patch where it will stay. I have decoded some of features but I am still not able to reproduce them. I'll really appreciate any help !
My understanding what the procedure could accomplish:
to move-turtles
ifelse perceptdist = 0
[ifelse patch-ahead 1 != nobody
[rt random moveangle lt random moveangle
let xcorhere [pxcor] of patch-here
let ycorhere [pycor] of patch-here
fd 1
let xcornext [pxcor] of patch-here
let ycornext [pycor] of patch-here
set dist sqrt (xcor * xcor + ycor * ycor)
set t_dispers (t_dispers + 1)
set energy (energy - (1 / efficiency))
let flightdistnow sqrt ((xcornext - xcorhere) * (xcornext - xcorhere) + (ycornext - ycorhere) * (ycornext - ycorhere))
set flightdist (flightdist + flightdistnow)
][]]
[let np patches in-radius perceptdist ; find the patch with the highest totalattract value within perception range
let bnp max-one-of np [totalattract]
let ah [totalattract] of patch-here
let xcorhere [pxcor] of patch-here
let ycorhere [pycor] of patch-here
let abnp [totalattract] of bnp
; -- why this ifelse condition is here ansd why they use these numbers?? ---
ifelse abnp - ah > 2 and random-float 1 < 0.1
[move-to bnp ; move to the patch with the highest attractivity value
let xbnp [pxcor] of bnp
let ybnp [pycor] of bnp
let flightdistnow sqrt ((xbnp - xcorhere) * (xbnp - xcorhere) + (ybnp - ycorhere) * (ybnp - ycorhere))
set t_dispers (t_dispers + flightdistnow)
set energy (energy - (flightdistnow / efficiency)) ; how the turtle decision to stay/move further is made - ratio of turtle energy/efficiency
set flightdist (flightdist + flightdistnow)
set dist sqrt (xcor * xcor + ycor * ycor)
[rt random moveangle lt random moveangle
set dist sqrt (xcor * xcor + ycor * ycor)
set t_dispers (t_dispers + 1)
set energy (energy - (1 / efficiency))
let xcorhere2 [pxcor] of patch-here
let ycorhere2 [pycor] of patch-here
fd 1
let xcornext2 [pxcor] of patch-here
let ycornext2[pycor] of patch-here
set dist sqrt (xcor * xcor + ycor * ycor)
let flightdistnow sqrt ((xcornext2 - xcorhere2) * (xcornext2 - xcorhere2) + (ycornext2 - ycorhere2) * (ycornext2 - ycorhere2))
set flightdist (flightdist + flightdistnow)
end
来源：https://stackoverflow.com/questions/32319606/netlogo-how-to-make-the-calculation-of-turtle-movement-easier