创建 PDF 版本时出现 LaTeX 错误。这通常表示 Rd 问题。发现 LaTeX 错误：！未定义的控制序列

Question

我是乳胶新手。我正确安装了 MikTeX 2.9、GhostScript、GSView、TeXnicCenter，并正确进行了设置。

我的包裹（名为“mypackage”）通过包裹检查
通过
从 R 控制台：devtools::check("C:/Users/User/Documents/Revolution/mypackage")
从 DOS 命令提示符：R CMD check mypackage
没有任何问题，我最终自动获得了 mypackage.PDF 文件。

我决定生成数学表达式，例如，

在生成的 .PDF 文件中。因此，我在 .R 文件的行中添加了以下乳胶表达式：

#' @param max selected ...The default is Schwert's approximation: \eqn{\lfloor 12(length(t) \over 100)^{\sfrac{1}{4}} \rfloor}

我再次激活并触发了上述包检查。这次，在包检查中，我收到以下错误（在命令提示符中）：

* checking PDF version of manual ...Warning: running command '"C:/Revolution/R-Enterprise-7.3/R-3.1.1/bin/x64/Rcmd.exe" Rd2pdf  --batch --no-preview --build-dir
="C:/Users/User/AppData/Local/Temp/RtmpysnRGn/Rd2pdf1b3050f426ea" --no-clean -o mypackage-manual.pdf  

"C:/Users/User/Documents/Revolution/mypackage.Rcheck/mypackage"' had status 1
 WARNING LaTeX errors when creating PDF version. This typically indicates Rd problems. LaTeX errors found: ! Undefined control sequence.
<argument> ...oor 12(length(t) \over 100)^{\sfrac
    {1}{4}} \rfloor
l.67 ...th(t) \over 100)^{\sfrac{1}{4}} \rfloor}{}

checking PDF version of manual without hyperrefs or index ...Warning: running command '"C:/Revolution/R-Enterprise-7.3/R-3.1.1/bin/x64/Rcmd.exe" Rd2pdf  --bat
ch --no-preview --build-dir="C:/Users/User/AppData/Local/Temp/RtmpysnRGn/Rd2pdf1b3069b07b94" --no-clean --no-index -o  mypackage-manual.pdf  

C:/Users/User/Documents/Revolution/mypackage.Rcheck/mypackage' had status 1 ERROR

我做了什么：我分析了 SOF 中的类似错误，但无法弄清楚出了什么问题。我不确定错误发生在哪里：我的乳胶语法或 R 中的东西。

如果有任何帮助，我将不胜感激。

编辑（根据 Werner 的评论完成序言；在实施以下解决方案之后）：

#' adfcs
#'
#' Augmented Dickey-Fuller test that uses common (sub-)sample for all of the lags when a selected max order is given to find optimal minimal lag order of the autoregressive process.
#'
#' Augmented Dickey-Fuller test (for unit root testing) that uses common (sub-)sample for all of the lags when a selected max order is given to find optimal minimal lag order of the autoregressive process. 
#' The test is based on J.G. McKinnons' numerical distribution functions. 
#' MacKinnon, J.G. (1996); Numerical distribution functions for unit root and cointegration tests, J of Applied Econometrics 11, p. 601 618.
#' The default value of max is Schwert's approximation (Schwert, G.W. (1989). Tests for Unit-Roots: A Monte Carlo investigation. Journal of Business and Economic Statistics 7, 147-159.) 
#' Usage: adfcs(t, max = floor(12*(length(t)/100)^(1/4)), type = c("c")). I thank Fabian Scheipl, Dept. of Statistics, LMU Munich for his helpful suggestions during the construction of adfcs. 
#' When data frame is supplied for the parameter t, specify the column of the variable for which the ADF test is wanted .
#'
#' @param t a numeric vector or time series object whose stationarity is examined
#' @param max selected max lag order to find optimal minimal lag order for the autoregressive process in ADF test. The default is Schwert's approximation: \eqn{\left\|12\left(\frac{length(t)}{100}\right)^{1/4}\right\|}
#' @param type a character string describing the type of the unit root  regression. Valid choices are "nc" for a regression  with no intercept (constant) nor time trend, and "c"  for a regression with an intercept (constant) but no time  trend, "ct" for a regression with an intercept  (constant) and a time trend. The default is "c".
#' @return Augmented Dickey-Fuller test that uses common sample for all of the lags.
#' @author Erdogan Cevher erdogancevher@@gmail.com
#' @seealso \code{\link{VARomlop}}
#' @examples
#' ## ADF test for the 1st variable in granger.df, max length is that of Schwert's approximation (default).
#' # adfcs(granger.df[,1])
#' ## ADF test for the 3rd variable in granger.df, max length is 10.
#' # adfcs(granger.df[,3], 10)
#' @importFrom fUnitRoots unitrootTest
#' @export
adfcs <- function(...

Answer 1

1.我找到了一个免费的在线/实时/所见即所得的乳胶转换器：https://www.codecogs.com/latex/eqneditor.php

在本网站；通过反复试验，我发现了 Schwertz 公式的乳胶语法：

\left\|12\left(\frac{length(t)}{100}\right)^{1/4}\right\|

（我建议通过空格（单击上面的数学符号时）将乳胶标签彼此分开，以进一步发现/了解乳胶标签的工作。）删除标签之间的所有空格不会影响结果数学表达。

2.然后，我将上面的codecogs的乳胶代码替换为\eqn{...}标签：

#' @param max selected ...The default is Schwert's approximation: \eqn{\left\|12\left(\frac{length(t)}{100}\right)^{1/4}\right\|}

我没有在 .R 文件的序言中添加任何内容。

3. 然后，我从 DOS 命令提示符重新触发了R CMD check mypackage。

这一次，包裹检查没有任何问题。我获得了 .PDF 文件，其中上述 .jpg 的内容比照显示。

（如果我能执行 Werner 的解决方案，我也会把它放在这里）