3D plott whit log scale on x and y and divide inside the plot base

Hi, I try to make this formula plotted in 3D to visualice something for a traning i should hold.

a=7.89e9; b=7.11e8; c=8.98e6; d=2.85e-14; f=linspace (1000,300000,31); B=linspace (1,4000,31); [X,Y]=meshgrid(f, B); Loss=(f/((a/B.^3)+(b/B.^2.3)+(c/B.^1.65)))+(d*B.^2*f.^2); mesh(f,B,Loss); surfe(f,B,Loss);

And this wont work, have tried a lot of things and noe progress. I se this is related to singular or division inside the formular, but i cant understand why this docent work. Trided this on Graphing calculator and then i get some out, but the presentation and log scale is not working on that so fare either. So i like to find a way to do this in Matlab as this is more convinient and powerfull for the future.

Answer 1

[Star Strider]

You created ‘X’ and ‘Y’ (corresponding to ‘f’ and ‘B’) correctly. You need to completely vectorize the ‘Loss’ calculation, and use them in it. Use a set call to set the axis scales.

Loss=(X./((a./Y.^3)+(b./Y.^2.3)+(c./Y.^1.65)))+(d*Y.^2.*X.^2);

figure(1)
mesh(f,B,Loss)
set(gca, 'XScale','log', 'YScale','log')

figure(2)
surf(f,B,Loss)
set(gca, 'XScale','log', 'YScale','log')

[Arne Steinstad]

Great, this solved it all, just now need to find out how to set the x,y,z values right to show it good. like to show B from 10-5000, f from 100-300000 and then z from 0 -5000. And then find a way to get the colours displayed in this correc, first atempt was only showing black.. But ths ws a realy good imrovment after 12 houers of errors.. thanks a lot for the support Star Strider

[Star Strider]

As always, my pleasure.

Experiment with this code to customise your axis labels:

figure(1)
mesh(f,B,Loss)
xtix = get(gca, 'XTick');
ytix = get(gca, 'YTick');
xtlbl = regexp(sprintf('%.0f\n', xtix), '\n', 'split');
ytlbl = regexp(sprintf('%.0f\n', ytix), '\n', 'split');
set(gca, 'XScale','log', 'YScale','log')
set(gca, 'XTick',xtix, 'XTickLabel',xtlbl(1:end-1), 'XTickLabelRotation',-30)
set(gca, 'YTick',ytix, 'YTickLabel',ytlbl(1:end-1), 'YTickLabelRotation',+30)
xlabel('f')
ylabel('B')
zlabel('Loss')
axis tight

I am not certain what you want, however this should get you started. See the documentation on Axis Properties (link) for more information.