MATLAB: Index and sort through vector by only picking the values that are the same

Question

H = [500 500 500 450 450 450 400 400 350 350 350 300 300 300];

I = [-0.0019 -0.0018 -0.0017 -0.0019 -0.0018 -0.0017 -0.0019 -0.0018 -0.0017]

V = [-7.54E-06 -7.23E-06 -6.93E-06 -7.53E-06 -7.21E-06 -6.89E-06 -6.60E-06 -7.50E-06 -7.23E-06 -6.90E-06]

Need to sort through the data and get an IV for each value but lump then off the uniqueness of their value, e.g., I want all the IVs for the H at 400, etc. I know there is a unique function in Matlab, but that only gives me a single element of the array that is unique. Is there a way to loop through the unique values to get the IV values?

Thanks,

Tyler

Answer 1

The unique funciton can have 3 outputs, although you have to specifically request them. The third output is the index of each repeated unique value in the vector. You can use those to map into ‘I’ and ‘V’:

H = [500 500 500 450 450 450 400 400 350 350 350 300 300 300];
[Hu,~,idx] = unique(H, 'stable')

The 'stable' argument simply retains the original order, rather than sorting the output.