help graph dot dialog: graph dot
-------------------------------------------------------------------------------
Title
[G] graph dot -- Dot charts (summary statistics)
Syntax
graph dot yvars [if] [in] [weight] [, options]
where yvars is
(asis) varlist
or is
[(stat)] varname [[(stat)] ...]
[(stat)] varlist [[(stat)] ...]
[(stat)] [name=]varname [...] [[(stat)] ...]
where stat may be any of
mean median p1 p2 ... p99 sum count min max
or
any of the other stats defined in [D] collapse
mean is the default. p1 means the first percentile, p2 means the
second percentile, and so on; p50 means the same as median. count
means the number of nonmissing values of the specified variable.
options description
---------------------------------------------------------------------
group_options groups over which lines of dots are
drawn
yvar_options variables that are the dots
linelook_options how the lines of dots look
legending_options how yvars are labeled
axis_options how numerical y axis is labeled
title_and_other_options titles, added text, aspect ratio, etc.
---------------------------------------------------------------------
group_options description
---------------------------------------------------------------------
over(varname[, over_subopts]) categories; option may be repeated
nofill omit empty categories
missing keep missing value as category
allcategories include all categories in the dataset
---------------------------------------------------------------------
yvar_options description
---------------------------------------------------------------------
ascategory treat yvars as first over() group
asyvars treat first over() group as yvars
percentages show percentages within yvars
cw calculate yvar statistics omitting
missing values of any yvar
---------------------------------------------------------------------
linelook_options description
---------------------------------------------------------------------
outergap([*]#) gap between top and first line and
between last line and bottom
linegap(#) gap between yvar lines; default is 0
marker(#, marker_options) marker used for #th yvar line
pcycle(#) marker styles before pstyles recycle
linetype(dot|line|rectangle) type of line
ndots(#) # of dots if linetype(dot); default is
100
dots(marker_options) look if linetype(dot)
lines(line_options) look if linetype(line)
rectangles(area_options) look if linetype(rectangle)
rwidth(relativesize) rectangle width if linetype(rectangle)
[no]extendline whether line extends through plot
region margins; extendline is usual
default
lowextension(relativesize) extend line through axis (advanced)
highextension(relativesize) extend line through axis (advanced)
---------------------------------------------------------------------
legending_options description
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legend_option control of yvar legend
nolabel use yvar names, not labels, in legend
yvaroptions(over_subopts) over_subopts for yvars; seldom
specified
showyvars label yvars on x axis; seldom
specified
---------------------------------------------------------------------
axis_options description
---------------------------------------------------------------------
yalternate put numerical y axis on right (top)
xalternate put categorical x axis on top (right)
exclude0 do not force y axis to include 0
yreverse reverse y axis
axis_scale_options y-axis scaling and look
axis_label_options y-axis labeling
ytitle(...) y-axis titling
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title_and_other_options description
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text(...) add text on graph; x range [0,100]
yline(...) add y lines to graph
aspect_option constrain aspect ratio of plot region
std_options titles, graph size, saving to disk
by(varlist, ...) repeat for subgroups
---------------------------------------------------------------------
The over_subopts -- used in over(varname, over_subopts) and, on rare
occasion, in yvaroptions(over_subopts) -- are
over_subopts description
---------------------------------------------------------------------
relabel(# "text" ...) change axis labels
label(cat_axis_label_options) rendition of labels
axis(cat_axis_line_options) rendition of axis line
gap([*]#) gap between lines within over()
category
sort(varname) put lines in prespecified order
sort(#) put lines in height order
sort((stat) varname) put lines in derived order
descending reverse default or specified line
order
---------------------------------------------------------------------
aweights, fweights, and pweights are allowed; see weight and see note
concerning weights in [D] collapse.
Menu
Graphics > Dot chart
Description
graph dot draws horizontal dot charts. In a dot chart, the categorical
axis is presented vertically, and the numerical axis is presented
horizontally. Even so, the numerical axis is called the y axis, and the
categorical axis is still called the x axis:
. graph dot (mean) numeric_var, over(cat_var)
x
|
first group |......o..............
|
second group |..........o..........
. |
. |
+---------------------
0 2 4 6 8
The syntax for dot charts is identical to that for bar charts; see [G]
graph bar.
We use the following words to describe a dot chart:
x axis
|
Group 1 |..........o...............
Group 2 |..............o...........
Group 3 |..................o....... <- lines
Group 4 |......................o...
+--------------------------
0 1 2 3 4 5 <- y axis
The above dot chart contains four lines. The words used to describe a
line are
marker
/
.............o............
|--distance--| \
dots
group_options
over(varname[, over_subopts]) specifies a categorical variable over which
the yvars are to be repeated. varname may be string or numeric. Up
to two over() options may be specified when multiple yvars are
specified, and up to three over()s may be specified when one yvar is
specified; options may be specified; see Appendix: Examples of
syntax below.
nofill specifies that missing subcategories be omitted. For instance,
consider
. graph dot (mean) y, over(division) over(region)
Say that one of the divisions has no data for one of the regions,
either because there are no such observations or because y==. for
such observations. In the resulting chart, the marker will be
missing:
division 1 |...........o....
region 1 division 2 |....o...........
division 3 |.......o........
|
division 1 |..o.............
region 2 division 2 |................
division 3 |..........o.....
+----------------
If you specify nofill, the missing category will be removed from the
chart:
division 1 |...........o....
region 1 division 2 |....o...........
division 3 |.......o........
|
region 2 division 1 |..o.............
division 3 |..........o.....
+----------------
missing specifies that missing values of the over() variables be kept as
their own categories, one for ., another for .a, etc. The default is
to ignore such observations. An over() variable is considered to be
missing if it is numeric and contains a missing value or if it is
string and contains "".
allcategories specifies that all categories in the entire dataset be
retained for the over() variables. When if or in is specified
without allcategories, the graph is drawn, completely excluding any
categories for the over() variables that do not occur in the
specified subsample. With the allcategories option, categories that
do not occur in the subsample still appear in the legend, and
zero-height bars are drawn where these categories would appear. Such
behavior can be convenient when comparing graphs of subsamples that
do not include completely common categories for all over() variables.
This option has an effect only when if or in is specified or if there
are missing values in the variables. allcategories may not be
combined with by().
yvar_options
ascategory specifies that the yvars be treated as the first over() group.
When you specify ascategory, results are the same as if you specified
one yvar and introduced a new first over() variable. Anyplace you
read in the documentation that something is done over the first
over() category, or using the first over() category, it will be done
over or using yvars.
Suppose that you specified
. graph dot y1 y2 y3, ascategory whatever_other_options
The results will be the same as if you typed
. graph dot y, over(newcategoryvariable) whatever_other_options
with a long rather than wide dataset in memory.
asyvars specifies that the first over() group be treated as yvars.
When you specify asyvars, results are the same as if you removed the
first over() group and introduced multiple yvars. We said in most
ways, not all ways, but let's ignore that for a moment. If you
previously had k yvars and, in your first over() category, G groups,
results will be the same as if you specified k*G yvars and removed
the over(). Anyplace you read in the documentation that something is
done over the yvars or using the yvars, it will be done over or using
the first over() group.
Suppose that you specified
. graph dot y, over(group) asyvars whatever_other_options
Results will be the same as if you typed
. graph dot y1 y2 y3 ..., whatever_other_options
with a wide rather than long dataset in memory. Variables y1, y2,
..., are sometimes called the virtual yvars.
percentages specifies that marker positions be based on percentages that
yvar_i represents of all the yvars. That is,
. graph dot (mean) inc_male inc_female
would produce a chart with the markers reflecting average income.
. graph dot (mean) inc_male inc_female, percentage
would produce a chart with the markers being located at
100*inc_male/(inc_male+inc_female) and
100*inc_female/(inc_male+inc_female).
If you have one yvar and want percentages calculated over the first
over() group, specify the asyvars option. For instance,
. graph dot (mean) wage, over(i) over(j)
would produce a chart where marker positions reflect mean wages.
. graph dot (mean) wage, over(i) over(j) asyvars percentages
would produce a chart where marker positions are
100*( mean_ij / (Sum_i mean_ij) )
cw specifies casewise deletion. If cw is specified, observations for
which any of the yvars are missing are ignored. The default is to
calculate each statistic by using all the data possible.
linelook_options
outergap(*#) and outergap(#) specify the gap between the top of the graph
to the beginning of the first line and the last line to the bottom of
the graph.
outergap(*#) specifies that the default be modified. Specifying
outergap(*1.2) increases the gap by 20%, and specifying outergap(*.8)
reduces the gap by 20%.
outergap(#) specifies the gap as a percentage-of-bar-width units.
graph dot is related to graph bar. Just remember that outergap(50)
specifies a sizable but not excessive gap.
linegap(#) specifies the gap to be left between yvar lines. The default
is linegap(0), meaning that multiple yvars appear on the same line.
For instance, typing
. graph dot y1 y2, over(group)
results in
group 1 |..x....o........
group 2 |........x..o....
group 3 |.......x.....o..
+----------------
In the above, o represents the symbol for y1 and x the symbol for y2.
If you want to have separate lines for the separate yvars, specify
linegap(20):
. graph dot y1 y2, over(group) linegap(20)
group 1 |.......o........
|..x.............
|
group 2 |...........o....
|........x.......
|
group 3 |.............o..
|.......x........
+----------------
Specify a number smaller or larger than 20 to reduce or increase the
distance between the y1 and y2 lines.
Alternatively, and generally preferred, is specifying option
ascategory, which will result in
. graph dot y1 y2, over(group) ascategory
group 1 y1 |.......o........
y2 |..o.............
|
group 2 y1 |...........o....
y2 |........o.......
|
group 3 y1 |.............o..
y2 |.......o........
+----------------
linegap() affects only the yvar lines. If you want to change the gap
for the first, second, or third over() groups, specify the
over_subopt gap() inside the over() itself.
marker(#, marker_options) specifies the shape, size, color, etc., of the
marker to be used to mark the value of the #th yvar variable.
marker(1, ...) refers to the marker associated with the first yvar,
marker(2, ...) refers to the marker associated with the second, and
so on. A particularly useful marker_option is mcolor(colorstyle),
which sets the color of the marker. For instance, you might specify
marker(1, mcolor(green)) to make the marker associated with the first
yvar green. See [G] colorstyle for a list of color choices, and see
[G] marker_options for information on the other marker_options.
pcycle(#) specifies how many variables are to be plotted before the
pstyle of the markers for the next variable begins again at the
pstyle of the first variable - p1dot (with the markers for the
variable following that using p2dot and so on). Put another way, #
specifies how quickly the look of markers is recycled when more than
# variables are specified. The default for most schemes is
pcycle(15).
linetype(dot), linetype(line), and linetype(rectangle) specify the style
of the line.
linetype(dot) is the usual default. In this style, dots are used to
fill the line around the marker: ........o........
linetype(line) specifies that a solid line be used to fill the line
around the marker: --------o--------
linetype(rectangle) specifies that a long "rectangle" (which looks
more like two parallel lines) be used to fill the area around the
marker: ========o=======
ndots(#) and dots(marker_options) are relevant only in the linetype(dots)
case.
ndots(#) specifies the number of dots to be used to fill the line.
The default is ndots(100).
dots(marker_options) specifies the marker symbol, color, and size to
be used as the dot symbol. The default is to use dots(msymbol(p)).
See [G] marker_options.
lines(line_options) is relevant only if linetype(line) is specified. It
specifies the look of the line to be used; see [G] line_options.
rectangles(area_options) and rwidth(relativesize) are relevant only if
linetype(rectangle) is specified.
rectangles(area_options) specifies the look of the parallel lines
(rectangle); see [G] area_options.
rwidth(relativesize) specifies the width (height) of the rectangle
(the distance between the parallel lines). The default is usually
rwidth(.45); see [G] relativesize}.
noextendline and extendline are relevant in all cases. They specify
whether the line (dots, a line, or a rectangle) is to extend through
the plot region margin and touch the axes. The usual default is
extendline, so noextendline is the option. See [G] region_options
for a definition of the plot region.
lowextension(relativesize) and highextension(relativesize) are advanced
options that specify the amount by which the line (dots, line or a
rectangle) is extended through the axes. The usual defaults are
lowextension(0) and highextension(0). See [G] relativesize.
legending_options
legend_option allows you to control the legend. If more than one yvar is
specified, a legend is produced. Otherwise, no legend is needed
because the over() groups are labeled on the categorical x axis. See
> [G] legend_option.
nolabel specifies that, in automatically constructing the legend, the
variable names of the yvars be used in preference to "mean of
varname" or "sum of varname", etc.
yvaroptions(over_subopts) allows you to specify over_subopts for the
yvars. This is seldom specified.
showyvars specifies that, in addition to building a legend, the
identities of the yvars be shown on the categorical x axis. If
showyvars is specified, it is typical to also specify legend(off).
axis_options
yalternate and xalternate switch the side on which the axes appear.
yalternate moves the numerical y axis from the bottom to the top;
xalternate moves the categorical x axis from the left to the right.
If your scheme by default puts the axes on the opposite sides,
yalternate and xalternate reverse their actions.
exclude0 specifies that the numerical y axis need not be scaled to
include 0.
yreverse specifies that the numerical y axis have its scale reversed so
that it runs from maximum to minimum.
axis_scale_options specify how the numerical y axis is scaled and how it
looks; see [G] axis_scale_options. There you will also see option
xscale() in addition to yscale(). Ignore xscale(), which is
irrelevant for dot plots.
axis_label_options specify how the numerical y axis is to be labeled.
The axis_label_options also allow you to add and suppress grid lines;
see [G] axis_label_options. There you will see that, in addition to
options ylabel(), ytick(), ymlabel(), and ymtick(), options xlabel(),
..., xmtick() are allowed. Ignore the x*() options, which are
irrelevant for dot charts.
ytitle() overrides the default title for the numerical y axis; see [G]
axis_title_options. There you will also find option xtitle()
documented, which is irrelevant for dot charts.
title_and_other_options
text() adds text to a specified location on the graph; see [G]
added_text_options. The basic syntax of text() is
text(#_y #_x "text")
text() is documented in terms of twoway graphs. When used with dot
charts, the "numeric" x axis is scaled to run from 0 to 100.
yline() adds vertical lines at specified y values; see [G]
added_line_options. The xline() option, also documented there, is
irrelevant for dot charts. If your interest is in adding grid lines,
see [G] axis_label_options.
aspect_option allows you to control the relationship between the height
and width of a graph's plot region; see [G] aspect_option.
std_options allow you to add titles, control the graph size, save the
graph on disk, and much more; see [G] std_options.
by(varlist, ...) draws separate plots within one graph; see [G]
by_option.
Suboptions for use with over() and yvaroptions()
relabel(# "text" ...) specifies text to override the default category
labeling. See the description of the relabel() option in [G] graph
bar for more information about this very useful option.
label(cat_axis_label_options) determines other aspects of the look of the
category labels on the x axis. Except for label(labcolor()) and
label(labsize()), these options are seldom specified; see [G]
cat_axis_label_options.
axis(cat_axis_line_options) specifies how the axis line is rendered.
This is a seldom specified option. See [G] cat_axis_line_options.
gap(#) and gap(*#) specify the gap between the lines in this over()
group. gap(#) is specified in percentage-of-bar-width units. Just
remember that gap(50) is a considerable, but not excessive width.
gap(*#) allows modifying the default gap. gap(*1.2) would increase
the gap by 20%, and gap(*.8) would decrease the gap by 20%.
sort(varname), sort(#), and sort((stat) varname) control how the lines
are ordered. See How bars are ordered and Reordering the bars in [G]
graph bar.
sort(varname) puts the lines in the order of varname.
sort(#) puts the markers in distance order. # refers to the yvar
number on which the ordering should be performed.
sort((stat) varname) puts the lines in an order based on a calculated
statistic.
descending specifies that the order of the lines -- default or as
specified by sort() -- be reversed.
Remarks
Remarks are presented under the following headings:
Relationship between dot plots and horizontal bar charts
Examples
Appendix: Examples of syntax
Relationship between dot plots and horizontal bar charts
Despite appearances, graph hbar and graph dot are in fact the same
command, meaning that concepts and options are the same:
. graph hbar y, over(group)
|---+
group 1 | |
|---+
|
|--------+
group 2 | |
|--------+
|
|--------------+
group 3 | |
|--------------+
|
+----------------
. graph dot y, over(group)
group 1 |...o............
group 2 |........o.......
group 3 |..............o.
+----------------
There is only one substantive difference between the two commands: Given
multiple yvars, graph hbar draws multiple bars:
. graph hbar y1 y2, over(group)
|-+
| |
group 1 |---+
| |
|---+
|
|---+
| |
group 2 |--------+
| |
|--------+
|
|-----+
| |
group 3 |--------------+
| |
|--------------+
|
+----------------
graph dot draws multiple markers on single lines:
. graph dot y1 y2, over(group)
group 1 |.x.o............
group 2 |...x....o.......
group 3 |.....x........o.
+----------------
The way around this problem (if it is a problem) is to specify option
ascategory or to specify option linegap(#). Specifying ascategory is
usually best.
Read about graph hbar in [G] graph bar.
Examples
Because graph dot and graph hbar are so related, the following examples
should require little by way of explanation:
. sysuse nlsw88
. graph dot wage, over(occ, sort(1))
ytitle("")
title("Average hourly wage, 1988, women aged 34-46", span)
subtitle(" ")
note("Source: 1988 data from NLS, U.S. Dept. of Labor,
Bureau of Labor Statistics", span)
(click to run)
. graph dot (p10) wage (p90) wage,
over(occ, sort(2))
legend(label(1 "10th percentile") label(2 "90th percentile"))
title("10th and 90th percentiles of hourly wage", span)
subtitle("Women aged 34-46, 1988" " ", span)
note("Source: 1988 data from NLS, U.S. Dept. of Labor,
Bureau of Labor Statistics", span)
(click to run)
. graph dot (mean) wage,
over(occ, sort(1))
by(collgrad,
title("Average hourly wage, 1988, women aged 34-46", span)
subtitle(" ")
note("Source: 1988 data from NLS, U.S. Dept. of Labor,
Bureau of Labor Statistics", span)
)
(click to run)
Appendix: Examples of syntax
Let us consider some graph dot commands and what they do:
graph dot revenue
One line showing average revenue.
graph dot revenue profit
One line with two markers, one showing average revenue and the
other average profit.
graph dot revenue, over(division)
#_of_divisions lines, each with one marker showing average
revenue for each division.
graph dot revenue profit, over(division)
#_of_divisions lines, each with two markers, one showing
average revenue and the other average profit for each division.
graph dot revenue, over(division) over(year)
#_of_divisions*#_of_years lines, each with one marker showing
average revenue for each division, repeated for each of the
years. The grouping would look like this (assuming 3 divisions
and 2 years):
division 1 |....o...............
year 1 division 2 |..........o.........
division 3 |..............o.....
|
division 1 |.o..................
year 2 division 2 |.......o............
division 3 |................o...
+--------------------
graph dot revenue, over(year) over(division)
Same as above, but ordered differently. In the previous
example, we typed over(division) over(year). This time, we
reverse it:
division 1 year 1 |....o...............
year 2 |.o..................
|
division 2 year 1 |..........o.........
year 2 |.......o............
|
division 3 year 1 |..............o.....
year 2 |................o...
+--------------------
graph dot revenue profit, over(division) over(year)
#_of_divisions*#_of_years lines each with two markers, one
showing average revenue and the other showing average profit
for each division, repeated for each of the years.
graph dot (sum) revenue profit, over(division) over(year)
#_of_divisions*#_of_years lines each with two markers, the
first showing the sum of revenue and the second showing the sum
of profit for each division, repeated for each of the years.
graph dot (median) revenue profit, over(division) over(year)
#_of_divisions*#_of_years lines each with two markers showing
the median of revenue and median of profit for each division,
repeated for each of the years.
graph dot (median) revenue (mean) profit, over(division) over(year)
#_of_divisions*#_of_years lines each with two markers showing
the median of revenue and mean of profit for each division,
repeated for each of the years.
Also see
Manual: [G] graph dot
Help: [G] graph bar; [D] collapse
