lin_anova_example.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}
{* 10mar2005}{...}
{* this hlp file called by testanova.dlg}{...}
{title:Examples of linear expressions to test after anova}

    After

{phang2}{cmd:. anova y x1 x2 x3 x1*x2 x1*x3 x2*x3 x1*x2*x3, continuous(x3)}

{pstd}
you test if the coefficients for the first and second levels of x1
are equal using the linear expression

	{cmd:_b[x1[1]] = _b[x1[2]]}

{pstd}
You test if the coefficient for the interaction of level 2 of x1 and level 1
of x2 is equal to the average of the coefficients for the interaction of
levels 1 and 3 of x1 and level 1 of x2 using

{phang2}{cmd:_b[x1[2]*x2[1]] = (_b[x1[1]*x2[1]] + _b[x1[3]*x2[1]])/2}

{pstd}
You test if the coefficient for the interaction of the continuous variable x3
with level 1 of x1 and level 2 of x2 is equal to the coefficient for the
interaction of x3 with level 2 of x1 and level 1 of x2 using

{phang2}{cmd:_b[x1[1]*x2[2]*x3] = _b[x1[2]*x2[1]*x3]}


{pstd}
{cmd:_coef} may be used in the place of {cmd:_b}.  For help with the
subscripting of categorical variables, try

{phang2}{cmd:. anova, detail}.


{title:Also see}

    Online:  {helpb anova}, {help anova postestimation}