 
In this video, you will learn to
create pie charts from summary
data using StatCrunch.
The data set I'm using is called
Categorical Variable in Summary
Form.
This is just a toy data set that
contains two columns of data.
The var1 column contains
unique observations
of a categorical variable,
and the counts column
contains the number of
times each associated value
in the var1 column was observed.
So in this case, the value
of B was observed 4 times
and the value of A
was observed 6 times.
Let's begin by
creating a pie chart.
To do so, under the graph menu
choose pie chart with summary.
In the categories
in box, I'll choose
the var1 column, and the counts
in box, I'll choose counts.
Click compute.
The resulting pie chart is
shown with a legend displaying
the values associated
with each color,
as well as the count and
percentage of each value.
So for example, the value
of A is shown in blue,
the count is 6, and it
represents 60% of the data.
 
StatCrunch allows the
user to display the count
and/or the percent in the
legend of their pie chart.
I would like to
display only percent.
So under the options
menu, I'll choose edit.
This takes us back to
the original window
where we built our pie chart.
In this window, StatCrunch
has other options for the user
to customize their pie chart.
In the display box I'm
going to deselect count.
To do that, I'll hold
down command on Mac
or control on a PC.
Now only percent of
total is highlighted.
I'll click compute,
and now only percent
is displayed in the legend.
Notice by default, StatCrunch
displays the values
in ascending order, or in
this case alphabetical order,
so that A is at the
top of the pie chart.
Also by default, StatCrunch
draws the first slice
of the pie chart at 0 degrees
in trigonometric terms,
or at 3 o'clock.
We can change both
of these defaults
back under the options menu.
 
In the order by box, it is set
to default to value ascending.
Value descending will
reverse this order.
Count ascending and
count descending
will order the pie chart by the
frequency of the values rather
than the values themselves.
For this example, I'll
choose value descending.
You will also notice
the start angle box.
It defaults to 0.
I'll change it to 90 degrees.
This will start our
pie chart at 90 degrees
in trigonometric terms,
or at 12 o'clock.
I'll click compute, and now
you can see the value of B
comes before the value of A,
and it begins at 12 o'clock.
StatCrunch also
provides the option
to combine values with a
small relative frequency
into an other category.
Back under options you'll notice
a box labeled other if percent
less than.
For this example, I'll enter 50.
This will group all
values less than 50%
into one other category.
I'll click compute,
and as you can see,
the B values are now
labeled as other.
Also you will notice
that StatCrunch
has changed the order of
the values in the pie chart.
The other category will never
begin at the starting angle.
As you can see, this is
really not a great idea
for this data set, but it
shows how StatCrunch can create
this category if it is needed.
