how to avoid for loop

can this 'for loop' be replaced? thanks in advance

counts=[];

for i=1 : length(b)-1

c=length(tof( tof >= b(i) & tof < b(i+1)) ) ;

counts=[counts,c];

end

Answer 1

[Jan]

A ,ore efficient version of the loop:

nb     = numel(b) - 1;
counts = zeros(1, nb);   % Pre-allocation!!!
for i = 1:nb
   counts(i) = sum(tof >= b(i) & tof < b(i+1));
end

Is tof a scalar or a vector? Is b sorted? Are you looking for histcounts ?

Pre-allocation is essential, because letting an array grow iteratively is extremely expensive.

[sb]

this loop works well and is 1.5 times faster. tof is a scaler, b is sorted, I am looking at histcouts without matlab's inbuilt code.

[Image Analyst]

Not sure what that means exactly, but if you need more help, attach your data and the desired/expected output.

Answer 2

[Image Analyst]

Try this (untested)

lastIndex = length(b)-1;
indexes = (tof > b(1:lastIndex)) & (tof < b(2:lastIndex + 1));
counts = cumsum(indexes)