How to Correct Error: Can't Find Mean of List with no numbers

Question

我正在尝试让海龟（觅食者）根据平均巢穴气味报告器移动，该报告器应该报告全世界巢穴气味传播的平均值，从巢穴的 200 到120在世界的相反角落。但是，在巢中，触发了以下错误，我不明白为什么。卑鄙的巢香不是一串数字吗？我该如何纠正这个错误？

Can't find the mean of a list with no numbers: [].
error while forager 7 running MEAN
  called by procedure MEAN-NEST-SCENT-IN-CONE

to-report mean-nest-scent-in-cone [cone-distance angle angle-width ] ; ant procedure - reports the mean amount of nest-scent in cone
  rt angle
  let p patches in-cone cone-distance angle-width
  ;ask p [ show chemical ]
  if p = nobody [report 0]
  lt angle
  report (mean [nest-scent] of p)
end
`````````````````````````````````

Answer 1

您将 'p' 设置为补丁集，但您正在测试它是否是 'nobody'。代理集的原语是 any?。尝试替换：

if p = nobody [report 0]
lt angle
report (mean [nest-scent] of p)

和

ifelse any? p
[ lt angle
  report mean [nest-scent] of p
]
[ report 0 ]

How to Correct Error: Can't Find Mean of List with no numbers

How to Correct Error: Can't Find Mean of List with no numbers

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