Database Reference
In-Depth Information
3. To create a bar chart with this information, click Grid to open up the
visualization menu and then Column to create a columnar bar chart.
Now you should see each corpus listed along the bottom row with the
word count as the height of the column.
4. Since our desired visualization uses color to indicate the date the play
was written, drag
corpus_date
to the Color tab. You should then see
red and green bars.
5. The default aggregation that is used is
SUM()
, but for
corpus_date
,
this doesn't make sense; adding multiple dates together doesn't mean
anything. Moreover, the
~!SUM()
aggregation doesn't make sense here
because the
corpus_date
entries matching a particular
corpus
all
have the same value.
MIN()
is a better choice, although
MAX()
or
AVG()
would also produce the same visualization. Select the drop-down
menu in the Color tab and pick
MIN()
from the available options.
6. Remember from the Tableau example that two of the corpora have a
date of 0, which skews the coloring. On the right side, under Measures,
there are sliders that let you select the range to use. Pick something like
1500 as the minimum, which should give enough dynamic range so that
you can see the difference between the various plays.
Figure 13.9
shows
the final visualization, which shows the variation between the corpus
date and corpus length of Shakespeare's oeuvre.
