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    <p>I made a procedure that can be used to automatically generate a temporary table for bins according to a specified number or size, for later use with Ofri Raviv's solution.</p> <pre><code>CREATE PROCEDURE makebins(numbins INT, binsize FLOAT) # binsize may be NULL for auto-size BEGIN SELECT FLOOR(MIN(colval)) INTO @binmin FROM yourtable; SELECT CEIL(MAX(colval)) INTO @binmax FROM yourtable; IF binsize IS NULL THEN SET binsize = CEIL((@binmax-@binmin)/numbins); # CEIL here may prevent the potential creation a very small extra bin due to rounding errors, but no good where floats are needed. END IF; SET @currlim = @binmin; WHILE @currlim + binsize &lt; @binmax DO INSERT INTO bins VALUES (@currlim, @currlim+binsize); SET @currlim = @currlim + binsize; END WHILE; INSERT INTO bins VALUES (@currlim, @maxbin); END; DROP TABLE IF EXISTS bins; # be careful if you have a bins table of your own. CREATE TEMPORARY TABLE bins ( minval INT, maxval INT, # or FLOAT, if needed KEY (minval), KEY (maxval) );# keys could perhaps help if using a lot of bins; normally negligible CALL makebins(20, NULL); # Using 20 bins of automatic size here. SELECT bins.*, count(*) AS total FROM bins LEFT JOIN yourtable ON yourtable.value BETWEEN bins.minval AND bins.maxval GROUP BY bins.minval </code></pre> <p>This will generate the histogram count only for the bins that are populated. David West ought to be right in his correction, but for some reason, unpopulated bins do not appear in the result for me (despite the use of a LEFT JOIN — I do not understand why).</p>
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    1. POGetting data for histogram plot
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