Remove number from a matrix within a for loop

This script outputs an 1x3 matrix (timeszmn2). I want to make it so that this script removes the 3rd number in this matrix within the 'for' loop. How can I do this?

I would assume that I need to make it so that zmndynarray2 doesn't have this third value?

zmn2 = zpoint';
d =[diff(zmn2) 0];
zmndynarray2 = [];
for i=1:(length(d)-1)
    if d(i)*d(i+1)< 0 && d(i+1) > 0
        zmndynarray2 = [zmndynarray2 (i+1)];
    end
end
zmn2 = zpoint(zmndynarray2)
timeszmn2 = times(zmndynarray2)

[Walter Roberson]

It is not obvious to me that the output would be a vector of length 3?

It looks to me as if you could probably get the locations using strfind() . strfind() is only documented for character matches, but it is not restricted to character matches. For example,

s = sign(d);
strfind(d(1:end-1) < 0 & d(2:end) > 0)

or you could test more directly on zmn2(1:end-1) in relationship to zmn2(2:end)

Also kind of looks like you are trying to do a findpeaks() kind of operation.

[Elijah L]

I think what I am trying to do is narrow my criteria for what zmndynarray2 is.

For example, this is the graph I'm generating. I want to narrow my criteria so that "false minima" (e.g. the third point) are not detected.

[Walter Roberson]

Have you considered findpeaks of the negative of the data ?

[Elijah L]

Yes, I know I could easily use findpeaks or islocalmin but I would like to use a for loop as my algorithim

Answer 1

[Gaurav Garg]

Hey Elijah,

You can replace the third element by [ ] in the script.

Example -

a = [1 2 3];
a(3)
a(3) = [ ]

What you would get is -

ans =

     1     2