lincom.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}
{* 07feb2005}{...}
{cmd:help lincom}{right:dialog:  {bf:{dialog lincom}}}
{hline}

{title:Title}

{p2colset 5 19 21 2}{...}
{p2col :{hi:[R] lincom} {hline 2}}Linear combinations of estimators{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 16 2}
{cmd:lincom} {it:{help exp}} [{cmd:,} {it:options}]

{synoptset 10}{...}
{synopthdr}
{synoptline}
{synopt :{opt ef:orm}}generic label; {cmd:exp(b)}; the default{p_end}
{synopt :{opt or}}odds ratio{p_end}
{synopt :{opt hr}}hazard ratio{p_end}
{synopt :{opt ir:r}}incidence-rate ratio{p_end}
{synopt :{opt rr:r}}relative-risk ratio{p_end}
{synopt :{opt l:evel(#)}}set confidence level; default is {cmd:level(95)}{p_end}
{synoptline}
{p2colreset}{...}
{p 4 6 2}where {it:exp} is any linear combination of coefficients that is valid
syntax for {helpb test}.  Note, however, that {it:exp} must not contain an
equal sign.


{title:Description}

{pstd}
{cmd:lincom} computes point estimates, standard errors, t or z statistics,
p-values, and confidence intervals for linear combinations of coefficients
after any estimation command.  Results can optionally be displayed as odds
ratios, hazard ratios, incidence-rate ratios, or relative risk ratios.

{pstd}
To obtain linear combinations of estimators after {cmd:svy}, see 
{help svy postestimation}.


{title:Options}

{phang}
{opt level(#)} specifies the confidence level, as a percentage, for confidence
intervals.  The default is {cmd:level(95)} or as set by {helpb set level}.

{phang}
{opt eform}, {opt or}, {opt hr}, {opt irr}, and {opt rrr} all report
coefficient estimates as exp(b) rather than b.  Standard errors and confidence
intervals are similarly transformed.  Note that {opt or} is the default after
{helpb logistic}.  The only difference in these options is how the output is
labeled.

	Option{col 19}Label{col 32}Explanation{col 56}Example commands
	{hline 63}
	{cmd:eform}{col 19}{cmd:exp(b)}{col 32}Generic label
	{cmd:or}{col 19}{cmd:Odds Ratio}{col 32}Odds ratio{col 56}{helpb logistic}, {helpb logit}
	{cmd:hr}{col 19}{cmd:Haz. Ratio}{col 32}Hazard ratio{col 56}{helpb stcox}, {helpb streg}
	{cmd:irr}{col 19}{cmd:IRR}{col 32}Incidence-rate ratio{col 56}{helpb poisson}
	{cmd:rrr}{col 19}{cmd:RRR}{col 32}Relative rate ratio{col 56}{helpb mlogit}
	{hline 63}

{pmore}
Note that {it:{help exp}} may not contain any additive constants when you use
the {opt eform}, {opt or}, {opt hr}, {opt irr}, or {opt rrr} options.


{title:Examples}

{phang}{cmd:. regress y x1 x2 x3}{p_end}
{phang}{cmd:. lincom x2-x1}{p_end}
{phang}{cmd:. lincom 3*x1 + 500*x3}{p_end}
{phang}{cmd:. lincom 3*x1 + 500*x3 - 12}

{phang}{cmd:. logit low age lwd race2 race3 smoke ptd ht ui}{p_end}
{phang}{cmd:. lincom race2+smoke, or}

{phang}{cmd:. logistic low age lwd race2 race3 smoke ptd ht ui}{p_end}
{phang}{cmd:. lincom race2+smoke}

{phang}{cmd:. mlogit insure age male nonwhite site2 site3}{p_end}
{phang}{cmd:. lincom [Prepaid]male + [Prepaid]nonwhite}


{title:Also see}

{psee}
Manual:  {bf:[R] lincom}

{psee}
Online:  {helpb nlcom}, {help svy postestimation}, {helpb test}, {helpb testnl}
{p_end}