Piecewise Function with a Vector
4 views (last 30 days)
Show older comments
I am writing a matlab about my work.
There is a piecewise function in my code.
somelike:
sqrt(2*(1-P/3)) when P<0;
sqrt(4-2*(1-P/2)) when P>0
P is a vertor, P = 1.4-2/5*f + something;
f is 0:0.001:20
there is my question
I don't quite get how to do a piecewise function. Because nomarlly piecewise function look likes:
f(x)=1 when x>0
f(x)=2 when x<0
x is not a vector.
In my work, the P is a vector. I can not do 1.4-2/5*f + something > 0 or < 0
Therefore please help me and give me the idea of how to do it
Kind Regards
0 Comments
Accepted Answer
Walter Roberson
on 18 Apr 2012
function r = f(P)
r = NaN(size(P));
r(P<0) = sqrt(2*(1-P(P<0)/3));
r(P>0) = sqrt(4-2*(1-P(P>0)/2));
end
Notice this will give you NaN at the locations in which P is exactly 0, as you did not define the result for that case.
2 Comments
Walter Roberson
on 23 Apr 2012
Yes, the above code is vectorized, suitable for P being a vector.
If you change the > to >= as in your comment, then you can also change the NaN(size(P)) to zeros(size(P)) which will be more efficient.
More Answers (0)
See Also
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!