Logical indexing for two conditions

Hi I have this code:

Excess=zeros(size(Energy));
for i=1:length(Energy)
    if Energy(i)>= 20
        Excess(i)=Energy(i)-20;     
    end
end

I would like to replace the for loop using logical indexing. I would appreciate any help.

Best Regards,

Ritika

Answer 1

[Jan]

Excess = zeros(size(Energy));
m      = (Energy >= 20);
Excess(m) = Energy(m) - 20;

A simpler code, but without the wanted logical indexing:

Excess = max(0, Energy - 20);

[Ritika Srinivasan]

Thank you so much :)

[Ritika Srinivasan]

Hey @Jan could you please explain what this command does : Excess = max(0, Energy - 20); I would like to understand how it works or if you have any documentation to support that

[Jan]

Of course you can read the documentation of this command:

help max
doc max

Searching in the internet for "Matlab max" displays the online help: https://www.mathworks.com/help/matlab/ref/max.html

Matlab's documentation is very useful and much better than other manuals e.g. the help sections of Windows :-)

If a command does not do exactly, what you need, look at the "See also" line at the bottom, which suggests similar commands.