# How do i plot a histogram from grouped data rather than raw [duplicate]

I have a data which is grouped in the following format:

{{date1,count1},{date2,count2},...}


I want to make a Date Histogram of this data. Apparently the acceptable format for mathematica is {date1, date1,... (repeated count1 times), date2, date2,... (repeated count2 times), ...}

I can convert it into the this format but there counts are in the millions and make the data uselessly huge after i extract it using group by using sql.

Is there a way to plot this histogram?

• It is not quite clear what you're asking. It would be very helpful if could give a small dataset to work with and a concrete example of what the desired output is – yohbs Apr 19 '17 at 14:17
• I recommend the method in my answer there (even though it has the least votes). To use DateHistogram instead of Histogram, make sure that your dates are in AbsoluteTime format, i.e. instead of {2017, 4, 19} use AbsoluteTime[{2017, 4, 19}] – Szabolcs Apr 19 '17 at 14:18
• I don't quite understand, what's the difference between data1 and count1 exactly? – user6014 Apr 19 '17 at 14:18
• I thought this question was quite clear. Instead of {4,4,4,5,5,6,7} you have {dataPoint, count} pairs, i.e.{{4,3}, {5,2}, {6,1}, {7,1}}. – Szabolcs Apr 19 '17 at 14:23
• @Szabolcs yes that is what i want but the data is dates instead of numbers. – user13892 Apr 19 '17 at 14:31