Defining matlab logspace for semilogx plot

I am trying to plot a matlab semilogx plot. How can I define a logspace in matlab from 400 nm to 700 nm?

Thanks in advance,

Raj Patel.

[Raj Patel]

Thanks Ameer.

Answer 1

[Ameer Hamza]

x = logspace(log10(400e-9), log10(700e-9))