{smcl}
{* *! version 0.5.0 26May2009}{...}
{cmd:help gcprvalue}: Compute group differences in predictions \ 0.5.0 2009-05-26.
{hline}

{title:Title}

{p2colset 5 18 18 2}{...}
{p2col:{hi:gcprvalue} {hline 2}}Computes group differences in predicted probabilities by
running a pair of {cmd:prvalue} commands. Options simplify constructing predictions
for useful sets of values for the RHS variables. Essentially, the command is a wrapper 
for making it easier to use {cmd:prvalue}.{p_end}
{p2colreset}{...}

{title:Syntax}

{p 4 10 2}
{cmd:gcprvalue}
{cmd:,}
[
{cmdab:noint:eract} 
{cmdab:grand:mean}
{cmdab:group:mean}
{cmdab:cross:mean}
{cmd:x(}{it:variable}={it:value}{cmd:...)}
{cmd:xis(}{it:variable}={it:value}{cmd:)}
{cmd:reset}
{cmdab:mat:rix(}{it:string}{cmd:)}
{cmd:skip}
{cmdab:lab:el(}{it:string}{cmd:)}
{cmd:print}
{cmd:bounds}
{cmdab:t:itle(}{it:string}{cmd:)}
{cmdab:nov:al}
{cmdab:qui:etly}
{cmd:verbose}
]

{title:Description}

{pstd}
{opt gcprvalue} computes group differences in predicted probabilities along with
confidence intervals (upper and lower bounds) for the group differences in 
predictions. It can record the predictions to a matrix for later printing
with {cmd:gcresults}.

{title:Options}

{phang}
{opt nointeract} indicates that predictions should be based on the non-interaction model 
(i.e., only a dummy variable for group membership is included). 
By default, the interactive model is assumed.

{phang}
{opt grandmean} sets variables for both groups to the combined means.

{phang}
{opt groupmean} sets variables for each group to the means for their own group.

{phang}
{opt crossmean} sets variables for each group to the means for the other group.

{phang}
{opt x()} specifies the levels of RHS variables as with {cmd:prvalue}. 

{phang}
{opt xis()} is the value being varied in the row of the matrix. This is used by
{cmd:gcprgen} to record the x-axis values for the plots. 

{phang}
{opt matrix()} is the name of the matrix to hold the predictions. 

{phang}
{opt reset} will reset the matrix to null and start recording again.

{phang}
{opt label()} provides a text label for the row holding the predictions. 

{phang}
{opt skip} adds a blank row to the matrix to make it easier to read.

{phang}
{opt print} will print the matrix.

{phang}
{opt title()} is the title used as a header when printing the matrix

{phang}
{opt bounds} print the upper and lower bounds.

{phang}
{opt noval} suppresses printing the values set by {cmd:xis()}. 

{phang}
{opt verbose} prints the globals used.

{phang}
{opt quietly} surpresses output.

{title:Examples}

{phang}{cmd:. gcprvalue...}{p_end}

{title:Saved globals and variables}

{pstd}

{synoptset 15 tabbed}{...}
{p2col 5 15 19 2: Globals}{p_end}
{synopt:{cmd:a}}...to be added{p_end}
{synopt:{cmd:b}}...to be added{p_end}

{p2col 5 15 19 2: Variables}{p_end}
{synopt:{cmd:a}}...to be added{p_end}
{synopt:{cmd:b}}...to be added{p_end}
{p2colreset}{...}

INCLUDE help gc_adofooter