Counting the number of elements of a vector found between a range in another vector
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I have a column which contains a range of values in a column 'Range' and another vector containing specific values in a column 'entryTime'. How to output the number of elements found in column 'entryTime' within the column 'Range'.
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Guillaume
2018-12-7
Frankly, the way you've stored your data is rubbish and making your work much harder.
Firstly, Your ranges shouldn't be stored as char arrays. It should be a 2 x numranges matrix or table.
Secondly, since the rows of Range have absolutely nothing to do with the rows of entryTime, they shouldn't be stored together in the same table. That would avoid pointless storing nans in entryTime if there are more ranges or god knows what as a filler in Ranges if there are more entryTimes.
So let's fix this:
ranges = regexp(data.Range, '([^-]+)-(.+)', 'tokens', 'once'); %plenty of other ways to split the data
ranges = array2table(str2double(vertcat(ranges{:})), 'VariableNames', {'lowerbound', 'upperbound'})
entryTimes = data(:, 'entryTime');
entryTimes(isnan(entryTimes.entryTime), :) = []
Then your problem is trivial:
rangecount = rowfun(@(l, u) sum(entryTimes.entryTime >= l & entryTimes.entryTime <= u), ranges, 'OutputVariableNames', {'count'})
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TADA
2018-12-6
编辑:TADA
2018-12-6
If you keep your range data as two columns instead of strings you can easily do it
et = data.entryTime(~isnan(data.entryTime));
% split ranges by '-' character
rng = cellfun(@(str) strsplit(str, '-'), data.Range, 'UniformOutput', false);
% Unravel cell array and parse numbers
ranges = str2double(vertcat(rng{:}));
% find which entry times are within any of the ranges
entryTimesInRangeMask = arrayfun(@(t) any(t >= ranges(:,1) & t <= ranges(:,2)), et);
% output number of elements within any of the ranges
disp(['Number of entry times within range: ' num2str(sum(entryTimesInRangeMask))]);
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