Formulation to Matlab code

3 Ansichten (letzte 30 Tage)
Maroco Sc
Maroco Sc am 14 Mai 2019
Beantwortet: Steven Lord am 14 Mai 2019
How to write this formulation in Matlab:
2.JPG
is it :
for i=1:N
S(i) = -PT(i) * log(PT(i));
end
  2 Kommentare
Dimitris Kalogiros
Dimitris Kalogiros am 14 Mai 2019
What is the base of the logarithm? Is it 10 ? If so, then you must use log10() .
Maroco Sc
Maroco Sc am 14 Mai 2019
I have checked several papers, they did not mention the base of logarithm. if it is 10, then the code will be:
for i=1:N
S(i) = -PT(i) * log10(PT(i));
end
Right?

Melden Sie sich an, um zu kommentieren.

Akzeptierte Antwort

Steven Lord
Steven Lord am 14 Mai 2019
There's no need to loop. The log and log10 functions can operate on arrays of data, and as long as you use element-wise multiplication you can do this in one line. [Actually, I'll need two; one to create sample data and one for the actual operation.]
PT = 10*rand(10);
S = -PT.*log10(PT);
You can compare this with the result of doing the same operation one element at a time to see if they're different.
S2 = zeros(size(PT));
for whichelement = 1:numel(PT)
S2(whichelement) = -PT(whichelement).*log10(PT(whichelement));
end
S-S2

Weitere Antworten (1)

Raj
Raj am 14 Mai 2019
Since your equation asks for 'log' not 'ln' , I think the code should be:
for i=1:N
S(i) = -PT(i) * log10(PT(i));
end

Tags

Produkte


Version

R2018b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by