一般的公式都可以，但加了\begin{array}之类的就不好用了。不知怎么解决。
公式确信没有问题，装换过来黏贴在tikz生成的tex文件中的相应位置可以运行。
报错信息：
File: pgfcoreexError in getMetricsFromLatex(TeXMetrics) :
TeX was unable to calculate metrics for the following string
or character:
$\left(\begin{array}{ccc}
Common reasons for failure include:
* The string contains a character which is special to LaTeX unless
escaped properly, such as % or $.
* The string makes use of LaTeX commands provided by a package and
the tikzDevice was not told to load the package.
