Latex报"Missing $ inserted"的解决方法

出现错误说明：

编译出现这样的错误。原因是在图的caption里使用了下标线“_”。因为latex会把它作为有特殊意义的标号或作为数学模式(math mode)进行编译。

\begin{figure*}[t]
%\setlength{\abovecaptionskip}{20pt}
 % \addtolength{\subfigcapskip}{5pt}
\normalsize
  \centering
  \subfigure[Queue Length of E_1]{  //说明：就是这里的下标线出错，改成E\_1即可
    \label{xx} %% label for first subfigure
    \includegraphics[height=5.2cm, width=3.5cm,angle=270]{.eps}}
    %\hspace*{-5.0em}
  \subfigure[***]{
    \label{fig:cachefib:time} %% label for second subfigure
    \includegraphics[height=5.2cm, width=3.5cm,angle=270]{.eps}}
   % \hspace*{-5.0em}
  \subfigure[***]{
  \label{fig:cachefib:cache-ratio} %% label for third subfigure
    \includegraphics[height=5.2cm, width=3.5cm,angle=270]{.eps}}
    %\hspace*{-5.0em}
  \subfigure[***]{
  \label{fig:cachefib:fib-ratio} %% label for forth subfigure
    \includegraphics[height=5.2cm, width=3.5cm,angle=270]{3.eps}}
   \caption{\small *****.}
  \label{fig:cachefib} %% label for entire figure
\end{figure*}

LaTeX常见错误提示及其原因简析

Latex Error Classes

较为模糊的错误

This is a list of error classes with ambiguos error messages. Here either the errors are have different causes and the message output is same or else the errors have the same root cause but the messages are different.

S.No	Class	错误提示信息	错误原因简析
1	e_des	! LaTeX Error: There's no line here to end	Usage of \\ at the end of a long label in 'description' environment
2	e_center	! LaTeX Error: There's no line here to end	Usage of \\ after the heading line in 'center' environment
3	e_foot	! Argument of \@sect has an extra }	Usage of a fragile command 'footnote' within \section
4	e_ragged	! Argument of \@caption has an extra }	Usage of \\ within \raggedright or \raggedleft environment
5	e_and	! Extra alignment tab has been changed to \cr	Too many &s in a row of a table or array or eqnarray.
6	e_cline	! Extra alignment tab has been changed to \cr	Reference no non existing column in \cline
7	e_col	! Extra alignment tab has been changed to \cr.	Usage @ in tabular* environment
8	e_num	! Missing number treated as zero	Usage of non numeric parameter after \\
9	e_asterisk	Missing * at the end of the line	* is not printed when used without brace after \\
10	e_pbox_miss	! Missing number, treated as zero.	\parbox[t]{} ..Missing argument to parbox
11	e_mis_circle	! Missing number, treated as zero.	Missing numeric parameter to \circle
12	e_list	! Argument of \lst@next has an extra }	Usage of 1stlisting inside fragile command \parbox
13	e_capacity	! TeX capacity exceeded, sorry [input stack size=1500]	Usage of 1stlisting inside fragile command \parbox
14	e_runaway	Runaway argument?	Generally because of missing braces, e.g \cline{1-2 instead of \cline{1-2}
15	e_verbatim	Runaway argument?	Usage of verbatim within scope of another command e.g: \ifthenelse
16	e_undefined	! Undefined control sequence	Usage of an unknown command
17	e_footnote	! Undefined control sequence	Usage of \footnote within \footnote
18	e_integral	! Missing { inserted.	Integral bounds are malformed
19	e_zeta	! Missing { inserted.	Extra subscript before integral upper limit term
20	e_bezier	! Illegal unit of measure (pt inserted).	Missing numeric argument to \qbezier
21	e_too_bezier	! Illegal unit of measure (pt inserted).	Too many arguments to \qbezier
22	e_unit	! Illegal unit of measure (pt inserted)	\parbox[t]{2} ..Illegal unit of second parameter
23	e_symfoot	! LaTeX Error: Counter too large.	More than 9 footnotes when using symbolic footnotes
24	e_large_count	! LaTeX Error: Counter too large.	Trying to display a corresponding letter for a counter vallue >26
25	e_begin	! LaTeX Error: Missing \begin{document}	Either text has been placed before \begin{document} or \begin{document} is missing
26	e_margin	! LaTeX Error: Missing \begin{document}.	Misuse of \marginsize

---

常见错误

S.No	Class	错误提示信息	错误原因简析
1	e_fileEnd	! File ended while scanning use of \end.	Generally caused because of missing a brace
2	e_end	No message only an asterisk, i.e *	Missing \end{document}
3	e_illegal	LaTeX Error: Illegal character in array arg	Usage of a letter other than r,l and c in tabular environment
4	e_tab	! Misplaced alignment tab character &	Missing \begin{tabular} while using tabular environment
5	e_backslash	! Missing \endcsname inserted	Usage of a backslash in front of the name of an environment, e.g \begin{\itemize}
6	e_delimiter	! LaTeX Error: Bad math environment delimiter	Missing \right immediately after the array environment
7	e_right	! Extra \right	\right has no matching \left OR \end{array} is missing
8	e_package	! LaTeX Error: Can only be used in preamble	Usage of \usepackage outside the preamble
9	e_math	! Missing $ inserted	Missing a starting or ending $ in Math mode, e.g m_e instead of $m_e$
10	e_parameter	! Illegal parameter number in definition of...	Usage of parameter number greater than the number of parameters defined in \newcommand, e.g \newcommand{\test}[1]{#3}
11	e_cmd	! LaTeX Error: Command ... already defined	Trying to define already existing command, e.g \newcommand{\time}
12	e_caption	! LaTeX Error: \caption outside float	\caption{...} used outside table environment
13	e_braces	! Too many }'s	Missing \begin{table}statement
14	e_parbox	! Argument of \@caption has an extra }	Usage of \parbox in a \caption
15	e_item	! LaTeX Error: Something's wrong--perhaps a missing \item	Missing \item within enumerate environment
16	e_fraction	! Argument of \end has an extra }	Misuse of fraction cmd e.g \frac{1,2}
17	e_verb	! LaTeX Error: \verb ended by end of line	Newline after \verb, e.g. \verb*dir*
18	e_invalid	! LaTeX Error: Command \end{itemize} invalid in math mode	Missing $ while using math mode in \itemize
19	e_equation	! Display math should end with $$	Usage of $$ inside equation mode
20	e_column	! Misplaced \omit	Usage of \newcommand and \multicolumn within tabular environment
21	e_subscript	! Double subscript.	Usage of double subscript
22	e_cls	! LaTeX Error: File `artcle.cls' not found.	Missing .sty or .cls file
23	e_nofile	! LaTeX Error: File `file1.tex' not found.	Missing file1.tex, e.g. \input{file1.tex}
24	e_sty	! LaTeX Error: File `anysize1.sty' not found	Use of unavailable package
25	e_doc_class	! LaTeX Error: Can be used only in preamble.	Usage of \documentclass outside preamble
26	e_circle	! LaTeX Error: Command \circle invalid in math mode.	Usage of \circle in math mode
27	e_picture	! Use of \pictur@ doesn't match its definition.	Bad parameter to \picture
28	e_line	! Use of \put dosen't match its definition	Badly formatted \line directive
29	e_line_arg	! LaTeX Error: Bad \line or \vector argument.	Bad \line parameter
30	e_counter	! LaTeX Error: No counter '10' defined.	Counter undefined
31	e_outer	! LaTeX Error: Not in outer par mode.	Using figure inside parbox
32	e_minipage	! LaTeX Error: Not in outer par mode.	Using figure minipage
33	e_lost	! LaTeX Error: Float(s) lost.	Counter undefined
34	e_lonely	! LaTeX Error: Lonely \item--perhaps a missing list environment.	Usage of \item outside list environment
35	e_parg	! LaTeX Error: Missing p-arg in array arg.	Missing p argument in tabular environment
36	e_hash	! You can't use `macro parameter character #' in vertical mode.	Usage of # in normal mode
37	e_enlarge	! LaTeX Error: Suggested extra height (14454.0pt) dangerously large.	Too big a number given in \enlargethispage
38	e_deftab	! LaTeX Error: Undefined tab position.	Undefined tabbing
39	e_pushtab	! LaTeX Error: \pushtabs and \poptabs don't match.	Unequal numbers of push and pop tabs
40	e_overtab	! LaTeX Error: Tab overflow.	Too many \= in tabbing environment
41	e_nest	! LaTeX Error: Too deeply nested.	Too many list environments
42	e_eqnarray	! LaTeX Error: Too many columns in eqnarray environment.	More than three columns in eqnarray
43	e_classpkg	! LaTeX Error: \usepackage before \documentclass.	Usage of usepackage before loading documentclass
44	e_load	! LaTeX Error: Two \LoadClass commands.	More than one load class command
45	e_require	! LaTeX Error: \RequirePackage or \LoadClass in Options Section.	RequirePackage may not be used with \DeclareOption
46	e_twoclass	! LaTeX Error: Two \documentclass or \documentstyle commands.	More than one documentclass declaration
47	e_font	! LaTeX Error: This NFSS system isn't set up properly.	Invalid font used in \DeclareErrorFont
48	e_superscript	! Double superscript.	Usage of two superscripts for the same variable, e.g. 2^3^4
49	e_clash_opt	! LaTeX Error: Option clash for package csvtools.	Clashing options for the same package
50	e_unknown_opt	! LaTeX Error: Unknown option ... for package ...	Unkown option for a package
51	e_hyphenation	! Improper \hyphenation will be flushed.	Improper parameter to \hyphenation
52	e_stack_size	! TeX capacity exceeded, sorry [main memory size=1000000]	Overflow of buffer due to mistake in command definition
53	e_environment	! LaTeX Error: Environment ... undefined.	Undefined environment
54	e_midline	! LaTeX Error: \< in mid line	Command \< may appear only at the beginning of a line
55	e_infinite	Goes into infinite loop	Usage of \\strut\hrule