twoway_rarea.hlp

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

{smcl}
{* 08apr2005}{...}
{cmd:help twoway rarea} {right:dialogs:  {dialog twoway_overlay:overlaid twoway}{space 0}}
	{right:{dialog twoway_simple:single twoway}{space 2}}
{hline}

{title:Title}

{p2colset 5 31 33 2}{...}
{p2col :{hi:[G] graph twoway rarea} {hline 2}}Range plot with area shading{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 60 2}
{cmdab:tw:oway}
{cmd:rarea}
{it:y1var} {it:y2var} {it:xvar}
{ifin}
[{cmd:,}
{it:options}]

{p2colset 9 30 32 2}{...}
	{it:options}{col 30}description
{p2line}
	{cmdab:vert:ical}{...}
{col 30}vertical area plot; the default
	{cmdab:hor:izontal}{...}
{col 30}horizontal area plot
	{cmd:sort}{...}
{col 30}recommended

INCLUDE help gr_areaopt

INCLUDE help gr_axlnk

INCLUDE help gr_twopt
{p2line}
{pin}
All explicit options are {it:unique}; see {help repeated options}.


{title:Description}

{pstd}
A range plot has two {it:y} variables, such as high and low daily stock prices
or upper and lower 95% confidence limits.

{pstd}
{cmd:twoway} {cmd:rarea} plots range as a shaded area.

{pstd}
Also see {helpb twoway area} for area plots filled to the axis.


{title:Options}

{phang}
{cmd:vertical}
and
{cmd:horizontal}
    specify whether the high and low {it:y} values are to be presented
    vertically (the default) or horizontally.

{pmore}
    In the default {cmd:vertical} case, {it:y1var} and {it:y2var} record
    the minimum and maximum (or maximum and minimum) {it:y} values to be
    graphed against each {it:xvar} value.

{pmore}
    If {cmd:horizontal} is specified, the values recorded in {it:y1var} and
    {it:y2var} are plotted in the {it:x} direction and {it:xvar} is treated
    as the {it:y} value.

{phang}
{cmd:sort}
    specifies that the data be sorted by {it:xvar} before plotting.

{phang}
{it:area_options}
    set the look of the shaded areas.  The most important of these options is
    {cmd:color(}{it:colorstyle}{cmd:)}, which specifies the color of both
    the area and its outline; see {it:{help colorstyle}} for a list of color
    choices.  See {it:{help area_options}} for information on the other
    {it:area_options}.

INCLUDE help gr_axlnkf

INCLUDE help gr_twoptf


{title:Remarks}

{pstd}
Remarks are presented under the headings

        {help twoway_rarea##remarks1:Typical use}
        {help twoway_rarea##remarks2:Advanced use}
        {help twoway_rarea##remarks3:Cautions}


{marker remarks1}{...}
{title:Typical use}

{pstd}
We have daily data recording the values for the S&P 500 in 2001:

	{cmd:. sysuse sp500, clear}

	{cmd:. list date high low close in 1/5}
	{txt}
	     {c TLC}{hline 11}{c -}{hline 9}{c -}{hline 9}{c -}{hline 9}{c TRC}
	     {c |} {res}     date      high       low     close {txt}{c |}
	     {c LT}{hline 11}{c -}{hline 9}{c -}{hline 9}{c -}{hline 9}{c RT}
	  1. {c |} {res}02jan2001   1320.28   1276.05   1283.27 {txt}{c |}
	  2. {c |} {res}03jan2001   1347.76   1274.62   1347.56 {txt}{c |}
	  3. {c |} {res}04jan2001   1350.24   1329.14   1333.34 {txt}{c |}
	  4. {c |} {res}05jan2001   1334.77   1294.95   1298.35 {txt}{c |}
	  5. {c |} {res}08jan2001   1298.35   1276.29   1295.86 {txt}{c |}
	     {c BLC}{hline 11}{c -}{hline 9}{c -}{hline 9}{c -}{hline 9}{c BRC}{txt}

{pstd}
We will use the first 57 observations from these data:

	{cmd:. twoway rarea high low date in 1/57}
	  {it:({stata "gr_example sp500: twoway rarea high low date in 1/57":click to run})}
{* graph gtrarea1}{...}


{marker remarks2}{...}
{title:Advanced use}

{pstd}
{cmd:rarea}
works particularly well when the upper and lower limits are smooth functions
and when the area is merely shaded rather than given an eye-catching color:

	{cmd}. sysuse auto, clear

	. quietly regress mpg weight

	. predict hat

	. predict s, stdf

	. gen low = hat - 1.96*s

	. gen hi  = hat + 1.96*s

	. twoway
		rarea low hi weight, sort color(gs14) ||
		scatter  mpg weight{txt}
	  {it:({stata "gr_example2 tworarea":click to run})}
{* graph tworarea}{...}

{pstd}
Notice the use of option {cmd:color()} to change the color
of the shaded area.  Also note that we graphed the shaded area first
and then the scatter.  Typing

	{cmd:. twoway scatter} ... {cmd:|| rarea} ...

{pstd}
would not have produced the desired result because the shaded area would
have covered up the scatterplot.

{pstd}
Also see {helpb twoway lfitci}.


{marker remarks3}{...}
{title:Cautions}

{pstd}
Be sure that the data are in the order of {it:xvar}, or specify {cmd:rarea}'s
{cmd:sort} option.  If you do neither, you will get something that looks like
modern art; see {hi:Cautions} in {helpb twoway area} for an example.


{title:Also see}

{psee}
Manual:  {bf:[G] graph twoway rarea}

{psee}
Online:  
{helpb twoway area};
{helpb twoway rbar},
{helpb twoway rspike},
{helpb twoway rcap},
{helpb twoway rcapsym},
{helpb twoway rline},
{helpb twoway rconnected},
{helpb twoway rscatter}
{p_end}