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plotting problem - empty graph

Posted 10 years ago
 f[x_] = ((x - 50000)^4.51846) (E^(50000 - x)) (4.6924*^-7) - this is my function. Plot[{f[x]}, {x, 0, 50000}] command gives me no GRAPH!!! What should i conclude? When i want to see the data points using "data = (InputForm@p)[[1, 1, 1, 3, 2, 1]]". I am not able to interpret the result!! something like this comes up... Graphics[GraphicsComplex[list of points......] Can anybody throw some light on this?
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Posted 10 years ago
 Same issue as http://community.wolfram.com/groups/-/m/t/284702 Be aware that clever things like data = (InputForm@p)[[1, 1, 1, 3, 2, 1]] are not guaranteed to be the same in different versions.
Posted 10 years ago
 Hi, there are several "issues" here. First of all (x - 50000)^4.51846 is complex for x<50000, e.g. (x - 50000)^4.51846 /. x -> 2 is -9.88935*10^19 + 1.70333*10^21 I. Plot does not plot complex numbers.The "interesting part of your graph is for x>50000. Also, you should plot f[x] instead of "f". f[x_] := ((x - 50000)^4.51846) (E^(50000 - x)) (4.6924^-7) Plot[f[x], {x, 50000, 50050}, PlotRange -> All] does work and gives a reasonable output:So, if you plot it for x< 50000 it will not produce a useful output, because the Plot function is not made to plot complex functions. Furthermore, the values that you want to plot are insanely large. Look at this: Table[Evaluate[f[x]], {x, 0, 5}] {-1.046106944790515*10^21730 + 1.801802763355185*10^21731 I, -3.848064616838928*10^21729 + 6.627862949115713*10^21730 I, -1.415495933981097*10^21729 + 2.438034178117325*10^21730 I, -5.206847948258534*10^21728 + 8.968215982373779*10^21729 I, -1.915319207666480*10^21728 + 3.298924128423410*10^21729 I, -7.045428821964528*10^21727 + 1.213496687279907*10^21729 I} In the interesting regime 50000
Posted 10 years ago
Posted 10 years ago
 I do not know why it returned GraphicsComplex instead of Line here. btw, you need to use := not = in the function definition. When asking questions, it helps to post complete self contained code you used all in one cell. This helps someone see what you actually typed. Include all definitions and commands used.