why my plot is not correct?
3 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
here is my code
x = -5:0.1:5
y = x.^(1/3)
plot(x,y)
2 Kommentare
Antworten (2)
Paul
am 11 Apr. 2021
If you're looking for a plot with odd symmetry, try:
plot(x,nthroot(x,3)) % check doc nthroot for details
0 Kommentare
DGM
am 11 Apr. 2021
I'm not sure what you intend the correct number to be. You're doing the cube root of negative numbers. They're going to be complex.
By default, plot() will only plot the real component of complex inputs. If you're expecting the plot to be symmetrical, consider plotting abs(y) to get the magnitude of the complex-valued region.
x = -5:0.1:5;
y = x.^(1/3);
h1=plot(x,real(y)); hold on
h2=plot(x,imag(y));
h3=plot(x,abs(y));
legend([h1,h2,h3],'real','imaginary','magnitude','location','southeast')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/579742/image.png)
2 Kommentare
DGM
am 11 Apr. 2021
You probably want Paul's answer below. nthroot() calculates the real root, whereas power() or .^ calculates the complex root. The web docs include such an example.
Siehe auch
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!