[?] Plot and set legends for these curves?

Questions
1

How do plot (or set) a legend for the 2 curves of this plot ?
Thanks for your support.

Plot[Table[-(10/\[CapitalDelta]t)*
   Log[\[CapitalDelta]P], {\[CapitalDelta]P, {2, 
    4}}], {\[CapitalDelta]t, 1, 60}, PlotLegends -> "Automatic"]
2

Hey, Christoph, how are you?
The following code (Evaluate) do the trick

Plot[Evaluate[Table[-(10/t)*Log[P], {P, {2, 4}}]], {t, 1, 60},
 PlotLegends -> {"One", "Two"}]

plot.png
plot.png440×229 9.9 KB

Hope that it is what you wanted.
See you.

3

Perfect, Thanks a lot, Estevao.
I have always difficulty to find the proper command in Mathematica.
How can we know one needs to use this command/function in this case?

And one more issue why it does not work with LogPlot:
LogPlot[Evaluate[Table[-(10/t)*Log[P], {P, {2, 4}}]], {t, 1, 60},
PlotLegends → {“One”, “Two”}]

4

In this case, you want to evaluate the Table first and then you need the variable t to plot it. The Evaluate function will run it without t and then the plot function will apply t on it. It is like, Evaluate will hold the equation with a variable (without a numerical result). You can check the documentation: Evaluate—Wolfram Documentation

In the LogPlot case, your function is not helping :).. So, i changed the minus sign to show you that it also works.

y = Table[(10/t)*Log[P], {P, {2, 4}}]
LogPlot[Evaluate@y,{t,1,1000},PlotLegends->{"One","Two"}]

and the result is

plot2.png
plot2.png446×224 10.6 KB

5

You could also plot it using the Plot3D function. You will be able to see it better

Plot3D[-(10/t)*Log[P],{P,2,4},{t,1,60},PlotLegends->{"Function"},AxesLabel->{"P","t","f(p,t)"}]

result:

plot4.png
plot4.png677×337 70.9 KB

6

Thanks a lot for your support Estevao. Plot appears now exactly as I want.
Great.
Cheers,