MATLAB: Comparing two vectos and inserting where numbers are missing

compare 2 vectors of different lenghtsinsert missing slots

Hi, Have tried various things. I have 2 vectors – a control vector called time (say m by 1) and a matrix call it b of (n by 2) m >n for example

time               b
1000               1000      5 
2000               2000      10
3000               4000      15
4000               5000      18
5000               6000      20
6000               8000      25
7000               9000      30
8000
9000
10000

i want matrix b to fill in the missing times (ie where missing) and a corresponding value in coloumn 2 of 0

so the output would look like

               1000      5   
               2000      10
               3000      0     (this line is new)
               4000      15     
               5000      18
               6000      20
               7000       0     (this line is new)         
               8000      25
               9000      30
               10000     0      (this line is new)
i have mangaged to index the missing spaces with

ind = find(ismember(time,b(:,1)) ==0) which returns 3 7 10 ie the missing places but not sure where to go. more than happy to ignore totlaly what i have done so far.

Best Answer

time = (1000:1000:10000).';
b = [1000      5; ...
     2000      10; ...
     4000      15; ...
     5000      18; ...
     6000      20; ...
     8000      25; ...
     9000      30];
found  = ismember(time, b(:, 1));
result(found, 2) = b(:, 2);
result(:, 1)     = time;

Related Solutions

MATLAB: How to compare the elements of a matrix and fill another matrix with the elements of a vector

Since your t matrix is full of 0 and 1 you can take advantage of that and just do this

a = [0.9 0.8 0.7 0.6 0.5];
b = [0.1 0.2 0.3 0.4 0.5];
t = ff2n(n);
t1 = t.*a
t1 =
         0         0         0         0         0
         0         0         0         0    0.5000
         0         0         0    0.6000         0
         0         0         0    0.6000    0.5000
         0         0    0.7000         0         0
         0         0    0.7000         0    0.5000
         0         0    0.7000    0.6000         0
         0         0    0.7000    0.6000    0.5000
         0    0.8000         0         0         0
         0    0.8000         0         0    0.5000
         0    0.8000         0    0.6000         0
         0    0.8000         0    0.6000    0.5000
         0    0.8000    0.7000         0         0
         0    0.8000    0.7000         0    0.5000
         0    0.8000    0.7000    0.6000         0
         0    0.8000    0.7000    0.6000    0.5000
    0.9000         0         0         0         0
    0.9000         0         0         0    0.5000
    0.9000         0         0    0.6000         0
    0.9000         0         0    0.6000    0.5000
    0.9000         0    0.7000         0         0
    0.9000         0    0.7000         0    0.5000
    0.9000         0    0.7000    0.6000         0
    0.9000         0    0.7000    0.6000    0.5000
    0.9000    0.8000         0         0         0
    0.9000    0.8000         0         0    0.5000
    0.9000    0.8000         0    0.6000         0
    0.9000    0.8000         0    0.6000    0.5000
    0.9000    0.8000    0.7000         0         0
    0.9000    0.8000    0.7000         0    0.5000
    0.9000    0.8000    0.7000    0.6000         0
    0.9000    0.8000    0.7000    0.6000    0.5000
t2 = not(t.*a).*b
t2 =
    0.1000    0.2000    0.3000    0.4000    0.5000
    0.1000    0.2000    0.3000    0.4000         0
    0.1000    0.2000    0.3000         0    0.5000
    0.1000    0.2000    0.3000         0         0
    0.1000    0.2000         0    0.4000    0.5000
    0.1000    0.2000         0    0.4000         0
    0.1000    0.2000         0         0    0.5000
    0.1000    0.2000         0         0         0
    0.1000         0    0.3000    0.4000    0.5000
    0.1000         0    0.3000    0.4000         0
    0.1000         0    0.3000         0    0.5000
    0.1000         0    0.3000         0         0
    0.1000         0         0    0.4000    0.5000
    0.1000         0         0    0.4000         0
    0.1000         0         0         0    0.5000
    0.1000         0         0         0         0
         0    0.2000    0.3000    0.4000    0.5000
         0    0.2000    0.3000    0.4000         0
         0    0.2000    0.3000         0    0.5000
         0    0.2000    0.3000         0         0
         0    0.2000         0    0.4000    0.5000
         0    0.2000         0    0.4000         0
         0    0.2000         0         0    0.5000
         0    0.2000         0         0         0
         0         0    0.3000    0.4000    0.5000
         0         0    0.3000    0.4000         0
         0         0    0.3000         0    0.5000
         0         0    0.3000         0         0
         0         0         0    0.4000    0.5000
         0         0         0    0.4000         0
         0         0         0         0    0.5000
         0         0         0         0         0
t1+t2
ans =
    0.1000    0.2000    0.3000    0.4000    0.5000
    0.1000    0.2000    0.3000    0.4000    0.5000
    0.1000    0.2000    0.3000    0.6000    0.5000
    0.1000    0.2000    0.3000    0.6000    0.5000
    0.1000    0.2000    0.7000    0.4000    0.5000
    0.1000    0.2000    0.7000    0.4000    0.5000
    0.1000    0.2000    0.7000    0.6000    0.5000
    0.1000    0.2000    0.7000    0.6000    0.5000
    0.1000    0.8000    0.3000    0.4000    0.5000
    0.1000    0.8000    0.3000    0.4000    0.5000
    0.1000    0.8000    0.3000    0.6000    0.5000
    0.1000    0.8000    0.3000    0.6000    0.5000
    0.1000    0.8000    0.7000    0.4000    0.5000
    0.1000    0.8000    0.7000    0.4000    0.5000
    0.1000    0.8000    0.7000    0.6000    0.5000
    0.1000    0.8000    0.7000    0.6000    0.5000
    0.9000    0.2000    0.3000    0.4000    0.5000
    0.9000    0.2000    0.3000    0.4000    0.5000
    0.9000    0.2000    0.3000    0.6000    0.5000
    0.9000    0.2000    0.3000    0.6000    0.5000
    0.9000    0.2000    0.7000    0.4000    0.5000
    0.9000    0.2000    0.7000    0.4000    0.5000
    0.9000    0.2000    0.7000    0.6000    0.5000
    0.9000    0.2000    0.7000    0.6000    0.5000
    0.9000    0.8000    0.3000    0.4000    0.5000
    0.9000    0.8000    0.3000    0.4000    0.5000
    0.9000    0.8000    0.3000    0.6000    0.5000
    0.9000    0.8000    0.3000    0.6000    0.5000
    0.9000    0.8000    0.7000    0.4000    0.5000
    0.9000    0.8000    0.7000    0.4000    0.5000
    0.9000    0.8000    0.7000    0.6000    0.5000
    0.9000    0.8000    0.7000    0.6000    0.5000

MATLAB: Add column to a matrix

a =[     0
    1.0000
    2.0000
    2.4000
    2.5000
    3.0000
    3.5000
    4.8000
    5.0000
    5.5000];
b =[      0 1.0000
    2.4000 2.0000
    4.8000 3.0000];
out = [a, b(cumsum(ismember(a,b(:,1))),2)]

[~,ii] = histc(a,[b(:,1);inf]);
out = [a, b(ii,2)]

Best Answer

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MATLAB: How to compare the elements of a matrix and fill another matrix with the elements of a vector

MATLAB: Add column to a matrix

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