--- loncom/html/adm/help/tex/Authoring_Output_Tags.tex 2017/01/21 00:02:05 1.24 +++ loncom/html/adm/help/tex/Authoring_Output_Tags.tex 2021/01/22 17:16:31 1.27 @@ -8,7 +8,8 @@ This group of tags generates useful outp \begin{verbatim} 2x^y+sqrt(3/x^2) \end{verbatim} -Expressions are displayed using the math expression display mechanism defined in the user's preferences. See the section below concerning the $<$m$>$ tag for more information on that as well as on the \textbf{display} attribute. +Expressions are displayed using the math expression display mechanism for the current context. The default is to use +the display mechanism the user has selected in preferences. This can be overriden by setting the \textbf{display} attribute for the tag. See the section below concerning the $<$m$>$ tag for more information on how the default is set and on the display attribute. Recognized functions are all trigonometric functions, and the following: exp, abs, logten, log, ln, sqrt, sgn, step, fact, int, lim, funX. @@ -17,8 +18,30 @@ exp, abs, logten, log, ln, sqrt, sgn, st O2 + 2H2 -> 2H2O \end{verbatim} will be rendered: - $\mathrm{O_2} + 2\,\mathrm{H_2} \to 2\,\mathrm{H_2O}$ + +\textbf{Syntax Description} +\begin{itemize} +\item Reactants are separated from products by `\texttt{->}'. +\item Individual reactants and products are separated by `\texttt{ +}' (leading space is obligatory). +\item Numbers preceding the first symbol of a chemical specie are considered to be stoichiometric coefficients. +\item Numbers appearing after the first symbol of a chemical specie are considered to be subscripts. +\item Superscripts are initialized by `\texttt{\^{}}' and terminated by a space. +\item Ionic charges are superscripts composed of a number followed by a sign (i.e. `\texttt{\^{}2+}'). +\end{itemize} + +\textbf{More examples} +\begin{itemize} +\item $\mathrm{Ca}(\mathrm{NO}_3)_2$ is written as:\\ +\texttt{Ca(NO3)2} +\item $\mathrm{OH}^- + \mathrm{H_3O}^+ \to 2\mathrm{H_2O}$ is written as:\\ +\texttt{OH\^{}- + H3O\^{}+ -> 2H2O} +\item $[\mathrm{Co}(\mathrm{H_2O})_6]^{2+} + 4\mathrm{Cl}^- \to [\mathrm{CoCl_4}]^{2-} + 6\mathrm{H_2O}$ is written as:\\ +\texttt{[Co(H2O)6]\^{}2+ + 4Cl\^{}- -> [CoCl4]\^{}2- + 6H2O} +\item $^3_1\mathrm{H} + ^2_1\mathrm{H} \to ^4_2\mathrm{He} + ^1_0\mathrm{n}$ is written as:\\ +\texttt{\^{}3 1H + \^{}2 1H -> \^{}4 2He + \^{}1 0n} +\end{itemize} + \item \textbf{num}\index{num}\index{format number}: Typesets a number formatted in scientific notation, fixed point, fixed point with commas, fixed point with commas and dollar sign, or in significant digits. \begin{verbatim} 31454678 results in 3.15 x 10^7 @@ -148,18 +171,24 @@ between the start and the end tag. By de When printing, the included text will be rendered in a visible box. -\item \textbf{m}\index{m}: The inside text is \LaTeX{}, and is converted +\item \textbf{m}\index{m}\index{equations}: The inside text is \LaTeX{}, and is converted to HTML (or MathML) on the fly. The default is to convert to the display mechanism that the user has selected in preferences. This can be overriden by setting the attribute \textbf{display} to one of ``\textbf{tth}'', ``\textbf{mimetex}'' or ``\textbf{mathjax}'' which -will force a specific display mechanism. Note that the ``\textbf{jsmath}'' display is deprecated today, and MathJax is used instead when it is specified. +will force a specific display mechanism. Note that the ``\textbf{jsmath}'' display is deprecated today, and MathJax is used instead when it is specified. If a display attribute is not included, the display mechanism is determined in the following order, with the first one set being the one in effect: +\begin{enumerate} +\item In course context: Course-wide default set by Course Coordinator via Settings $>$ Course Settings $>$ Display of resources $>$ Force use of a specific math rendering engine +\item User's own personal preference set by the user hovering over the user's name at top left of a LON-CAPA page, and selecting Preferences $>$ Math display settings +\item Domain default set by a Domain Coordinator +\item System default set for the LON-CAPA version installed on the server (tth in 2.11 and earlier, mathjax in 2.12). +\end{enumerate} The contents of \texttt{ } are interpreted as LaTeX outside math environment, which is why using \texttt{\$ \$} is needed to switch to the LaTeX math environment. However, the ``\textbf{mathjax}'' display (which is used by default in recent versions of LON-CAPA) interprets all the contents of \texttt{ } as math, and does not support non-math LaTeX. For content to work well with all the display mechanisms, it is therefore important to never use non-math LaTeX for web targets. Even purely for printing, it is better to avoid using non-math LaTeX, as the printing mechanism might use HTML instead of LaTeX in the future. If you want variables inside of this tag to be evaluated before the tex gets converted, then use eval=``on'' \index{eval=on}. For -example, \texttt{\$ \$eqn \$}, +example, \texttt{\$ \$eqn \$}, will evaluate the variable \$eqn first and then use the display mechanism. Anytime you use a variable inside of the m tag, you will want to set eval to on. @@ -172,13 +201,13 @@ For example, put the following in a scri and in a text area, you can type: -\texttt{\$ \$eqn \$} +\texttt{\$ \$eqn \$} You will get the equation rendered with no +-, no matter what value \$b may take on. -\item \textbf{lm}\index{lm}: This is another way to input math, which does not require +\item \textbf{lm}\index{lm}\index{equations}: This is another way to input math, which does not require knowing \LaTeX{}. The lm syntax describes mathematical operations rather than appearance (as opposed to LaTeX, which describes how the math should appear). Display is the same when the math operations are the same, for instance 2*(x) will be displayed just like 2x. One advantage to that system is that math will be displayed in a consistent way, even when written by several authors. The drawback is that display cannot be chosen precisely. Eventually, this syntax will also be used to evaluate \texttt{} (it is already used for the real-time preview). @@ -288,9 +317,9 @@ external image or a LON-CAPA resource. I \item \textbf{problemtype}\index{problemtype}: This tag allows you to show or hide output based on what the problem-type parameter is set to in the course. For example: \begin{verbatim} - -The formula for the circumference of a circle is 2*pi*r - + + The formula for the circumference of a circle is 2*pi*r + \end{verbatim} Will only show the output text when the problem is set to the type of exam or survey in the course. The attribute for mode can be set to show or hide. The attribute for for can be problem, exam, survey, or practice.