Number of peaks per interval

how can I count the number of peaks in a given time interval such that if there was no peak detected the count is 0.

This is what I have so far

[time peakcount] =

1 1

2 2

3 1

4 2

6 3

8 2

I would like to have something like this NB: row 5 and 7. thanks

[time peakcount] =

1 1

2 2

3 1

4 2

5 0

6 3

7 0

8 2

Answer 1

[Star Strider]

One approach:

t_pc = [ 1     1
         2     2
         3     1
         4     2
         6     3
         8     2];

t_pc2 = [min(t_pc):max(t_pc); zeros(1,numel(min(t_pc):max(t_pc)))].';
t_pc2(t_pc(:,1),2) = t_pc(:,2)

producing:

t_pc2 =
     1     1
     2     2
     3     1
     4     2
     5     0
     6     3
     7     0
     8     2

A more efficient version:

t_pc2 = (min(t_pc):max(t_pc)).';
t_pc2(t_pc(:,1),2) = t_pc(:,2)

.

Answer 2

[Alan Stevens]

How about:

newtime = 1:max(time);
newpeakcount(time) = peakcount;

[Priscilla]

Thanks Allan, but this returns the initial output

[Alan Stevens]

No. It returns the counts with the zeros added, albeit transposed (but that's easily fixed);

newtime =

1 2 3 4 5 6 7 8

newpeakcount =

1 2 1 2 0 3 0 2