Is this the correct syntax for replacing a specific element in a dependent vector?
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numElem = 9990;
w = linspace(2*pi,2*pi*10^18,numElem);
wRes = 2*pi*10^9;
for n = 1:numElem
if w(n) > wRes
w = [w(1:n), wRes, w(n:numElem)];
freq = w ./ (2*pi);
lambda = 299792458 ./ freq;
if w == wRes
B = 2*pi./lambda;
B = pi/2 .*w./wRes;
I am trying to create a range of w's and make sure that a specific value, wRes is in there. For that specific wRes, I want an exceptional value for B. Is the above code the correct way of going about it?
추가 답변 (1개)
Brendan Hamm 2016년 12월 27일
It looks like you are trying to change any values of w which are greater than wRes to be wRes instead, but you are instead placing an additional element into w at the (n+1)th position and then at the next iteration checking if that value is greater than wRes. I think what you are looking for is logical indexing.
idx = w > wRes;
The ith index of idx is true (1) if w(i) > wRes. Now you can use this to access the elements of w where idx is true and change only those values:
w(idx) = wRes;
Consider this on a simpler example:
x = 1:10;
idx = x > 5; % 6th through 10th elements are true!
x(idx) = -1; % 6th through 10th elements are now -1!