Index of the row

Hi,

I have a 5000 by 1 vector and I have a scalar, which is NOT part of the vector. I want to find the row number of the closest value to the scalar in the vector. The vector contains both positive and negative numbers and the scalar can be positive and negative too.

Anyone an idea of how to code this in Matlab.

Many thanks

Answer 1

[Azzi Abdelmalek]

[~,idx]=min(abs(your_vector-threshold))

[Imner Renmi]

Just to be sure, it will also work well for the negative values right?

Answer 2

[Star Strider]

This workd:

vector = randi([-99,99], 100, 1);                       % Create Data
scalar = 100*(rand-0.5);                                % Create Data
[vs,idx] = sort(vector);                                % Sort
q = find(vs <= scalar, 1, 'last');                      % Find Lowest Close Value
[q2,ixm] = min(vs([q, q+1]));                           % Mininmum Distance
nearest = vs(q+ixm-1)                                   % Result

[Imner Renmi]

What are 'vs' and 'idx'?

[Star Strider]

The ‘vs’ array is the sorted ‘vector’. The ‘idx’ vector are the original indices of the elements of the sorted vector. If you want the index instead of the value for ‘nearest’, that assignment becomes:

nearest_idx = idx(q+ixm-1)