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I have been trying to create a certain fractal with Mathematica but the main issue is that if I try and do something like

ComplexPlot[
  Nearest[{I, -2 + I, 3 - 2 I}, z], 
  {z, -2 - 2 I, 2 + 2 I}
]

and then try to graph it, I keep getting these error messages:

Nearest::neard: The default distance function does not give a real numeric distance when applied to the point pair z and I.
Nearest::neard The default distance function does not give a real numeric distance when applied to the point pair SystemComplexPlotsDumpnz$. and I.
General::stop: Further output of Nearest::neard will be suppressed during this calculation.

I have tried doing this with normal plot and real numbers, which works just fine, and I know that nearest can handle complex numbers as it can do things like Nearest[{I + 2, 3I}, 0] and will output 2 + I. So the issue is something with ComplexPlot. The final image given is also just a red square, which is unexpected. Anyone know how to help?

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    $\begingroup$ Perhaps an indirect approach might succeed: nf = Nearest[{I, -2 + I, 3 - 2 I}]; nfx[z_?NumericQ] := nf[z] and then try using nfx[z] instead in your plot. $\endgroup$
    – J. M.'s persistent exhaustion ♦
    Jun 20 at 17:47
  • $\begingroup$ @J.M. I tried that and the errors are no longer showing up but the output it still a large red box, which shouldn't be showing up $\endgroup$
    – Brandon Nadel
    Jun 20 at 17:53
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    $\begingroup$ Ah, if you tried evaluating nfx[] at some arbitrary argument, you'd find that it gives a list and not a number. Perhaps nfx[z_?NumericQ] := First[nf[z]] is what you wanted instead? $\endgroup$
    – J. M.'s persistent exhaustion ♦
    Jun 20 at 17:56
  • $\begingroup$ @J.M. that works, thanks $\endgroup$
    – Brandon Nadel
    Jun 20 at 18:01

1 Answer 1

Reset to default
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Clear[ne]
ne[z_?NumericQ] := Nearest[{I, -2 + I, 3 - 2 I}, z][[1]]
ComplexPlot[ne[z], {z, -2 - 2 I, 2 + 2 I}]

enter image description here

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