Comparing array elements of different lengths

I'm trying to compare two arrays that are different lengths. One array will always be smaller than the other.

Array1 - stores pulses given

Array2 - stores neurons spiking information

I want to go through Array2 and match it the correct pulse in Array 1 and get the difference between the times (spike delay).

One way I've thought of is to have it go through Array2 and compare this value so that it falls in between two values in Array1.

So if Array2 has 2.6

Array1: .5 1.0 1.5 2.0 2.5 3.0

If would go through array 1 and then match between 2.5 and 3.0. Then it would subtract from the first value (2.5) to get the difference .1 and store in a different array.

For every time it doesn't match between numbers, I want it to count that which is the f_count. It would mean that the neuron did not spike.

true_spike = zeros(length(array2));
spike_delay = zeros(length(array2));
f_count = 0;
for i = 1:length(array2)
    for j = 1:length(array1)
        if array2(i,1) <= array1(j+1,1) && array2(i,1) > array1(j,1)
            true_spike(i,1) = array2(i,1);
            spike_delay(i,1) = array2(i,1) - array1(j,1);
        else
            f_count = f_count + 1;
        end
    end
end
spike_delay(spike_delay==0) = [];
spike_delay = spike_delay';

[Ameer Hamza]

If possible, attach a sample dataset. It will help in properly understanding the question and suggesting a solution.

[Graduate Student]

Thanks, I am attaching an excel sheet containing Array1 and Array2. I color coded some of it I was going through and manually seeing the differences. The red is a pulse that was given where the neuron in Array2 did not respond.

[Ameer Hamza]

In your excel file, look at the cells D9 and D10. Is that a mistake? Both subtract B7 from A16 and A17. But B7 comes between A17 and A18, so shouldn't you only have A17-B7. Is this correct?

[Graduate Student]

In column D I was manuallly calculating what I wanted Matlab to do.

Array 1 = pulses given

Array 2 = Neurons response

However, the neuron doesn't respond to each pulse. I was highlighting that in red for myself. I did subtract is twice to see the spike delay value. Given what I said above, it should be A17-B7, giving you -0.22. But actually that spike is responding to A16 giving you a value of -7.32. The reason for this is because -0.22 is too small of a value for the experiment. But for now I want to work on first getting column D and work on cases like B7 after.

Answer 1

[Ameer Hamza]

The code gives the value according to the specified rule. The result matches with first few values in excel file

pulses = xlsread('Spiking_Example.xlsx', 'A:A');
neurons = xlsread('Spiking_Example.xlsx', 'B:B');
neurons(end) = []; % ignore last 0 in second column of excel file

difference = pulses - neurons';
mask = difference > 0;
[~, sub] = max(mask, [], 1);
sub = sub-1;
sub(sub==0) = size(difference,1);
index = sub2ind(size(difference), sub, 1:size(difference,2));
result = difference(index);