help connect_options
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Title
[G] connect_options -- Options for connecting data points with lines
Syntax
connect_options description
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connect(connectstyle) how to connect points
sort[(varlist)] how to sort before connecting
cmissing({y|n} ...) missing values are ignored
lpattern(linepatternstyle) line pattern (solid, dashed, etc.)
lwidth(linewidthstyle) thickness of line
lcolor(colorstyle) color of line
lstyle(linestyle) overall style of line
pstyle(pstyle) overall plot style, including linestyle
recast(newplottype) advanced; treat plot as newplottype
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All options are rightmost; see repeated options. If both sort and
sort(varlist) are specified, sort is ignored and sort(varlist) is
honored.
Description
The connect_options specify how points on a graph are to be connected.
In certain contexts (e.g., scatter; see [G] graph twoway scatter), the
lstyle(), lpattern(), lwidth(), and lcolor() options may be specified
with a list of elements, with the first element applying to the first
variable, the second element to the second variable, and so on. For
information about specifying lists, see [G] stylelists.
Options
connect(connectstyle) specifies whether points are to be connected and,
if so, how the line connecting them is to be shaped. The line
between each pair of points can connect them directly or in stairstep
fashion.
sort and sort(varlist) specify how the data be sorted before the points
are connected.
sort specifies that the data should be sorted by the x variable.
sort(varlist) specifies that the data be sorted by the specified
variables.
sort is the option usually specified. Unless you are after a special
effect or your data are already sorted, do not forget to specify this
option. If you are after a special effect, and if the data are not
already sorted, you can specify sort(varlist) to specify exactly how
the data should be sorted.
Specifying sort or sort(varlist) when it is not necessary will slow
graph down a little. It is usually necessary to specify sort if you
specify the twoway option by(), and especially if you include the
suboption total.
Options sort and sort(varlist) may not be repeated within the same
plot.
cmissing({y|n} ...) specifies whether missing values are to be ignored.
The default is cmissing(y ...), meaning that they are ignored.
Consider the following data:
+------------+
| rval x |
|------------|
1. | .923 1 |
2. | 3.046 2 |
3. | 5.169 3 |
4. | . . |
5. | 9.415 5 |
|------------|
6. | 11.538 6 |
+------------+
Say that you graph these data by using "line rval x" or equivalently
"scatter rval x, c(l)". Do you want a break in the line between 3
and 5? If so, you code
. line rval x, cmissing(n)
or equivalently
. scatter rval x, c(l) cmissing(n)
If you omit the option (or code cmissing(y)), the data are treated as
if they contained
+------------+
| rval x |
|------------|
1. | .923 1 |
2. | 3.046 2 |
3. | 5.169 3 |
4. | 9.415 5 |
5. | 11.538 6 |
+------------+
meaning that a line will be drawn between (3, 5.169) and (5, 9.415).
If you are plotting more than one variable, you may specify a
sequence of y/n answers.
lpattern(linepatternstyle), lwidth(linewidthstyle), lcolor(colorstyle),
and lstyle(linestyle) determine the look of the line used to connect
the points; see lines. Note the lpattern() option, which allows you
to specify whether the line is solid, dashed, etc.; see [G]
linepatternstyle for a list of line-pattern choices.
pstyle(pstyle) specifies the overall style of the plot, including not
only the linestyle but also all other settings for the look of the
plot. Only the linestyle affects the look of line plots. See [G]
pstyle for a list of available plot styles.
recast(newplottype) is an advanced option allowing the plot to be recast
from one type to another, for example, from a line plot to
scatterplot; see [G] advanced_options. Most, but not all plots,
allow recast().
Remarks
An important option among all the above is connect(), which determines
whether and how the points are connected. The points need not be
connected at all (connect(i)), which is scatter's default. Or the points
might be connected by straight lines (connect(l)), which is line's
default (and available in scatter). connect(i) and connect(l) are
commonly specified, but there are other possibilities, such as connect(J)
(which connects in stairstep fashion and is appropriate for empirical
distributions). See [G] connectstyle for a full list of your choices.
Equally as important as connect() is sort. If you do not specify this,
the points will be connected in the order in which they are encountered.
That can be useful when you are creating special effects, but, in
general, you want the points sorted into ascending order of their x
variable. That is what sort does.
The remaining connect options specify how the line is to look: Is it
solid or dashed? Is it red or green? How thick is it? Option
lpattern() can be of great importance, especially when printing to a
monochrome printer. For a general discussion of lines (which occur in
many contexts other than connecting points), see lines.
Also see
Manual: [G] connect_options
Help: [G] concept: lines; [G] colorstyle, [G] connectstyle, [G]
linestyle, [G] linepatternstyle, [G] linewidthstyle
