Is there a function to plot a function with logarithmic scale like 'semilogy' does?

46 views (last 30 days)
Shuangfeng Jiang on 16 Jul 2020
Commented: Walter Roberson on 16 Jul 2020
I would like to plot a function, and it seems that there's only 'fplot' that can do it as what I've got is just a function rather than a set of data. However, I would like to plot the function with logarithmic scale without assigning a set of input to the function, and 'semilogy' doesn't work as I don't have the input data but the specified input interval.
%% a very simple example
syms x
y(x)=exp(x);
f1=matlabFunction(y)% how to plot the function with logarithmic scale without assigning a set of input?
Therefore, is there a function like a combination of 'fplot' and 'semilogy', which can help us plot the function with logarithmic scale without assigning a set of input to the function?

Walter Roberson on 16 Jul 2020
Note that you can use fplot with Symbolic expressions and functions... but using matlabFunction can result in faster execution.
Anyhow, fplot and then set the axes properties XScale or YScale to 'normal' or 'log'
Walter Roberson on 16 Jul 2020
I can tell by the spacing that it is using log for the y axes. The 0.45 to 0.5 distance is about half of the 0.25 to 0.3 distance.