How Much and How Many - Communicating Data with Tableau - page 51

Figure 3-16. The histogram
Notice that Tableau has automatically created a new field in the Dimensions area called Re-
fuseTonsCollected (bin) . This data field type is used to determine the discrete intervals
into which the individual records are bucketed. The Rows shelf, which in this case determ-
ines the height of each bar, includes CNT(RefuseTonsCollected) . This field gives a value
according to the number of records in each bin.
How can we read this chart? The first bar of the chart shows that there were two records
(community districts, in this case) that produced between 1,000 and 1,500 tons of refuse
(technically 1,000 ≤ x < 1,500). The second bar, with a height of three, is for community dis-
tricts producing between 1,500 and 2,000 tons of refuse, and so on. The bin size is therefore
500 tons. You can easily see that the most common amount of refuse to be collected during
the month of September 2011 was between 2,000 and 2,500 tons (eight community districts
fell in that range).