How do I find the mean of a binary set for each value of no.1 to7

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Tracey Rochester
Tracey Rochester 2020-1-18
评论： TADA 2020-1-19
I have a vector row of 5,000 random no.s 1 to 7. I have a vector row of 5,000 1's and 0's as a second vector row. (This represents 5,000 tirials, where every time the random number was > 4, the machine chose 1, otherwise 0). I have put both vectors together in a matrix/array with the values on top row and the binaries on the second row. I have to calcualte the mean of the responses for each of the values. How do I do this please? I am beginner level and need my variables spelled out, to understand them. I think I use accumarray and mean but not sure how to compile the coding.
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Tracey Rochester
Tracey Rochester 2020-1-19
Thank you so much – your code is so clearly described! I too thought the Q rather ridiculous, given the perfect scores, however I think we have to find the mean because we are going to add human error in a future task, for which I will have to adopt the same principle. I'm going to work through this now... thanks again!! Not quite sure how 'double' generates a 1, and Matlab help is as clear as mud on it, but will play around with it a bit.
P.S. My way of creating what you have was much more long-winded with a for loop and if statement! But I guess as you get better at this, you quickly recognise simpler, more efficient ways :-)
comparisonStimulusValue = randi(7);
correct = [ ];
correctV = [ ];
comparisonStimulusValueV = [ ];
for iTrials = 1:5000; % Trial has 5,000 iterations...
comparisonStimulusValue(1) = randi(7);
if (comparisonStimulusValue > 4);
correct = 1;
correctV = [correctV correct];
comparisonStimulusValueV = [comparisonStimulusValueV comparisonStimulusValue];
correct = 0;
correctV = [correctV correct];
comparisonStimulusValueV = [comparisonStimulusValueV comparisonStimulusValue];
end
% End of conditional behaviours
end
% End of repeated loop
comparisonStimulusValuesAndResponsesM = [comparisonStimulusValueV; correctV];
TADA
TADA 2020-1-19
how 'double' generates a 1
What image analyst did there was to generate a logical vector which determines when the value is greater than 4:
b = topRow > 4
b =
0 1 0 0 0 0 0 1 0 1
Next this binary vector was converted to an array of double precision numbers by sending it to the double function
bottomrow = double(b);
Or in a single line of code as image analyst did

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