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I have a functionR1[x_, t_] = -((t^35 x^2)/10333147966386144929666651337523200000000); I use the following command in Mathematica to show the graph of Function

pic1 = Plot3D[Abs[R1[x, t]], {x, 0, 1}, {t, 0, 1}, PlotRange -> Full, AxesLabel -> {"x", "t"}, AxesEdge -> {{-1, -1}, {-1, -1}, {-1, 1}}, LabelStyle -> Directive[Black, Bold, 14], BoxStyle -> Directive[Thick, Black, 16], BoxRatios -> {1.5, 1.5, 1.5}, ViewPoint -> {-2, -2, 1}, PlotStyle -> Green]

The Image is not shown enter image description here

But when I am using the following Function

R2[x_, t_] = - ((t^35*x^2)/10333147966386144929666651337523200000);

I have just removed three zero from the denominator, Mathematica gives the Image of function using same code

pic1 = Plot3D[Abs[R2[x, t]], {x, 0, 1}, {t, 0, 1}, PlotRange -> Full, 
  AxesLabel -> {"x", "t"}, AxesEdge -> {{-1, -1}, {-1, -1}, {-1, 1}}, 
  LabelStyle -> Directive[Black, Bold, 14], 
  BoxStyle -> Directive[Thick, Black, 16], 
  BoxRatios -> {1.5, 1.5, 1.5}, ViewPoint -> {-2, -2, 1}, 
  PlotStyle -> Green]

The Image of Second Function is enter image description here

How we obtain the Image of 1st Function. I am using Mathematica 13.3.1

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  • $\begingroup$ for your first one, if you do Table[Abs[R1[x, t]], {x, 0, 1, .1}, {t, 0, 1, .1}] // Chop then you will see why. It is all zeros i.sstatic.net/ophxcsA4.png it looks like you hit a thresh hold on what Plot3D can show in terms of how small the values can be. For your R2 you did not hit this limit. $\endgroup$
    – Nasser
    Commented Nov 30 at 7:56
  • $\begingroup$ You can see this by changing the code to Plot3D[1000*Abs[R1[x, t]], {x, 0, 1}, {t, 0, 1}, PlotRange -> All] and now it shows plot. $\endgroup$
    – Nasser
    Commented Nov 30 at 7:59
  • $\begingroup$ Here is your R1 without Chop. You see how small the values are i.sstatic.net/HKIlaSOy.png $\endgroup$
    – Nasser
    Commented Nov 30 at 8:02
  • $\begingroup$ Too small. It is recommended to use Log scaling. $\endgroup$
    – cvgmt
    Commented Nov 30 at 8:27

1 Answer 1

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The smallest normalized single precision number is:

2^-128 // N

2.93874*10^-39

It looks like Plot3D truncates numbers smaller than same threshold approx. around this number:

 Plot3D[10^-38 2 (x), {x, 0, 1}, {y, 0, 1}]

enter image description here

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