# [tex-live] Equation Problem

Yue Wang yuleopen at gmail.com
Wed Jul 8 06:38:08 CEST 2009

this is not a texlive problem. you should mail this to the xetex
mailing list or the local user group forum.

2009/7/8 snvv <snvv101 at gmail.com>:
> Hello
>
> I have a problem with equations.
> When I use the following code
> $\hat{\vartheta}_{t|t} = \hat{\vartheta}_{t|t-1}+K_{t}\varepsilon_{t}$
>
> $\hat{\vartheta}_{t|t-1} = F\hat{\vartheta}_{t-1|t-1}$
>
> $\varepsilon_{t}=y_{t}-\varphi_{t}^{\prime}\hat{\vartheta}_{t|t-1}$
>
> $K=\frac{\sum_{t|t-1}\varphi_{t}}{\sigma_{e}^{2}+\varphi_{t}^{\prime}\sum_{t| > t-1}\varphi_{t}}$
>
> $\sum_{t|t-1}=F\sum_{t-1|t-1}F^{\prime}+GWG^{\prime}$
>
> $\sum_{t|t} =\sum_{t|t-1}-\frac{\sum_{t| > t-1}\varphi_{t}\varphi_{t}^{\prime}\sum_{t|t-1}} > {\sigma_{e}^{2}+\varphi_{t}^{\prime}\sum_{t|t-1}\varphi_{t}}$ \\
>
> Then the equations are just fine
>
> When I try to number the equations with the following code
> \begin{subequations}\label{grp}
> \begin{align}
> \hat{\vartheta}_{t|t} = \hat{\vartheta}_{t|t-1}+K_{t}\varepsilon_{t}\\
> \hat{\vartheta}_{t|t-1} = F\hat{\vartheta}_{t-1|t-1}\\
> \varepsilon_{t}=y_{t}-\varphi_{t}^{\prime}\hat{\vartheta}_{t|t-1}\\
> K=\frac{\sum_{t|t-1}\varphi_{t}}{\sigma_{e}^{2}+\varphi_{t}^{\prime}\sum_{t|
> t-1}\varphi_{t}}\\
> \sum_{t|t-1}=F\sum_{t-1|t-1}F^{\prime}+GWG^{\prime}\\
> \sum_{t|t} =\sum_{t|t-1}-\frac{\sum_{t|
> t-1}\varphi_{t}\varphi_{t}^{\prime}\sum_{t|t-1}}
> {\sigma_{e}^{2}+\varphi_{t}^{\prime}\sum_{t|t-1}\varphi_{t}}
> \sum_{t|t-1}F
> \end{align}
> \end{subequations}
>
> Then I have some problems.
> 1st the summation is to large (i.e see last equation in the attached file)
> 2nd the last equation is not numbered properly
> 3nd I use the xgreek package and the numbering in equations is in Greek (i.e