将Turtle变量除以Patch变量得出错误

Question

我正在写一些代码。乌龟和斑块设置为具有值。它们都没有零值。我正在尝试用农民周围DWS（补丁变量）的平均值来划分地表水（农民拥有）。我假设没有值是零，但得到除以零的错误。我要求找出错误并帮助我进行更正。这是代码

Globals [ Water-Availbility]
Breed [farmers farmer]
farmers-own [ WA sw ]  

patches-own [
GW wtd DWS] 
to setup
   clear-all
    setup-farmers
    ask patches [ ifelse random 4 = 0 [
    set dws  distance-from-water-source + random-float 50
    set WTD DWS / depth-WT + random-float 1
    set GW Ground-water + random-float 5.005  +  (100 / wtd)
    set pcolor blue
  ]

     [ set dws  distance-from-water-source + random-float 100 
       set WTD DWS / depth-WT + 5 + random-float 5 
       set GW Ground-water + random-float 5.005  +  (100 / wtd)
       set pcolor red]]
end
to setup-farmers

create-farmers num-farmers [move-to one-of patches
                             set shape "person"
                              set sw  random 100 + surface-water / sum [DWS] of patches in-radius 1 / count patches in-radius 1 
                              SET WA  sw +  sum [gw] of patches in-radius 1 / count patches in-radius 1 + [gw] of self
]
end

Answer 1

这似乎只是setup中的调度问题-在设置补丁之前调用setup-farmers，因此当农民查询时所有补丁的DWS都等于零那个价值。 sum [DWS] of patches in-radius 1因此为0，因此分母为零。将您的设置更改为以下内容，您应该一切顺利。

to setup
  clear-all
  ask patches [ 
    ifelse random 4 = 0 [
      set dws  50 + random-float 50
      set WTD DWS / 50 + random-float 1
      set GW 50 + random-float 5.005  +  (100 / wtd)
      set pcolor blue
    ] [ 
      set dws  50 + random-float 100 
      set WTD DWS / 50 + 5 + random-float 5 
      set GW 50 + random-float 5.005  +  (100 / wtd)
      set pcolor red 
    ]
  ]
  setup-farmers
  reset-ticks
end