# Multi-line Equation Problem in Latex

by S_David
Tags: equation, latex, multiline
 P: 74 I'm now using them for clusters of similar equations, so my index numbers don't get too outrageous. \begin{subequations}\begin{align} Y_1^{+1}(\theta,\phi) &= -\sqrt{\frac{3}{8\pi}}\sin\theta e^{i\phi} \\ Y_1^0(\theta,\phi) &= \sqrt{\frac{3}{4\pi}}\cos\theta \\ Y_1^{-1}(\theta,\phi) &= \sqrt{\frac{3}{8\pi}}\sin\theta e^{-i\phi} \end{align}\end{subequations}
 Sci Advisor P: 1,498 \begin{subequations} \begin{align} \frac{u(x_0+\Delta x)-u(x_0)}{\Delta x} &=\frac{du}{dx} + \frac{\Delta x}{2}\frac{d^2 u}{dx^2} +\cdots \\ \frac{u(x_0)-u(x_0-\Delta x)}{\Delta x} &=\frac{du}{dx} - \frac{\Delta x}{2}\frac{d^2 u}{dx^2} +\cdots \\ \frac{u(x_0+\Delta x)-u(x_0-\Delta x)}{\Delta x} &= \frac{du}{dx} + \frac{\Delta x^2}{6}\frac{d^3 u}{dx^3}+ \cdots \end{align} \end{subequations} Nice!! big fan!
 P: 7 Hi Fenn, I tried this but it didn't work. I don't know what else to do. Please help. TQ
 P: 74 Hi sni, Can you be more informative about what you are trying to do, and how it is not working?
 P: 7 i tried using \newln but the equation still exceeds the page.
 P: 74 Could you please post an example of what you are trying to do? These forums will parse LaTeX formatting if you enclose it within the a set of [ tex ] and [ /tex ] delimiters (remove the spaces to get them to work.) eg: $$\newcommand{\parenthnewln}[1]{\right.\\#1&\left.{}} \begin{split} f(x)=1+&g(x)\\ =1+&\left(x+x^2+\dots \parenthnewln{+}x^n+\ldots\right) \end{split}$$ You can also show your code verbatim by enclosing it in [ code ] and [ /code ] delimiters. \newcommand{\parenthnewln}[1]{\right.\\#1&\left.{}} $$\begin{split} f(x)=1+&g(x)\\ =1+&\left(x+x^2+\dots \parenthnewln{+}x^n+\ldots\right) \end{split}$$
 P: 7 $$\begin{eqnarray} \begin{split} \frac{1}{2}v(e^{X}P_{1}+2e^{X}\frac{\partial P_{1}}{\partial X}+e^{X}\frac{\partial^2 P_{1}}{\partial X^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X^2})+(r-\frac{1}{2}v)(e^{X}P_{1}+e^{X}\frac{\partial P_{1}}{\partial X}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial X}) \\ + \rho\sigma v(e^{X}\frac{\partial P_{1}}{\partial v}+e^{X}\frac{\partial^2 P_{1}}{\partial X\partial v} -Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X\partial v})+\frac{1}{2}v\sigma^2(e^{X}\frac{\partial^2 P_{1}}{\partial v^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial v^2}) +[\kappa(\theta-v)-\lambda v] \\ (e^{X}\frac{\partial P_{1}}{\partial v}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial v})-r(e^{X}P_{1}-Ke^{-r(T-t)}P_{2})+(e^{X}\frac{\partial P_{1}}{\partial t}-rKe^{-r(T-t)}\partial P_{2}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial t}) = 0 e^{X}\left[\frac{1}{2}v\frac{\partial^2 P_{1}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{1}}{\partial X\partial v}+\frac{1}{2}v\sigma^2\frac{\partial^2 P_{1}}{\partial v^2} +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{1}}{\partial v}+(r+\frac{1}{2}v)\frac{\partial P_{1}}{\partial X}+\frac{\partial P_{1}}{\partial t}\right] \\ - Ke^{-r(T-t)}\left[\frac{1}{2}v\frac{\partial^2 P_{2}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{2}}{\partial X\partial v}+\frac{1}{2}v\sigma^2\frac{\partial^2 P_{2}}{\partial v^2}+[\kappa(\theta-v)-\lambda v]\frac{\partial P_{2}}{\partial v}+(r-\frac{1}{2}v)\frac{\partial P_{2}}{\partial X}+\frac{\partial P_{2}}{\partial t}\right] &=& 0 \end{split} \end{eqnarray} [\tex]  P: 74 Here's a quick tweaking of your markup, where I have used a modified version of these \newln and \parenthnewln commands that I suggested in an earlier post: [tex] \newcommand{\newln}{\\&\hspace{2em}} \newcommand{\parenthnewln}{\right.\newln\left.{}} \begin{eqnarray} \begin{split} \frac{1}{2}v&(e^{X}P_{1}+2e^{X}\frac{\partial P_{1}}{\partial X}+e^{X}\frac{\partial^2 P_{1}}{\partial X^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X^2})&\newln % +(r-\frac{1}{2}v)(e^{X}P_{1}+e^{X}\frac{\partial P_{1}}{\partial X}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial X})&\newln % +\rho\sigma v(e^{X}\frac{\partial P_{1}}{\partial v}+e^{X}\frac{\partial^2 P_{1}}{\partial X\partial v} -Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X\partial v})\newln % +\frac{1}{2}v\sigma^2(e^{X}\frac{\partial^2 P_{1}}{\partial v^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial v^2})&\newln % +[\kappa(\theta-v)-\lambda v] (e^{X}\frac{\partial P_{1}}{\partial v}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial v})&\newln % -r(e^{X}P_{1}-Ke^{-r(T-t)}P_{2})\newln % +(e^{X}\frac{\partial P_{1}}{\partial t}-rKe^{-r(T-t)}\partial P_{2}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial t}) &= 0\\ % e^{X}&\left[\frac{1}{2}v\frac{\partial^2 P_{1}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{1}}{\partial X\partial v} % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{1}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{1}}{\partial v}+(r+\frac{1}{2}v)\frac{\partial P_{1}}{\partial X}+\frac{\partial P_{1}}{\partial t}\right]\newln % -Ke^{-r(T-t)}\left[\frac{1}{2}v\frac{\partial^2 P_{2}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{2}}{\partial X\partial v}\parenthnewln % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{2}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{2}}{\partial v}+(r-\frac{1}{2}v)\frac{\partial P_{2}}{\partial X}+\frac{\partial P_{2}}{\partial t}\right] &= 0 \end{split} \end{eqnarray}$$ For some reason the [ tex ] markup does not appear to be working properly, so I have included the code as well. \newcommand{\newln}{\\&\hspace{2em}} \newcommand{\parenthnewln}{\right.\newln\left.{}} \begin{eqnarray} \begin{split} \frac{1}{2}v&(e^{X}P_{1}+2e^{X}\frac{\partial P_{1}}{\partial X}+e^{X}\frac{\partial^2 P_{1}}{\partial X^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X^2})&\newln % +(r-\frac{1}{2}v)(e^{X}P_{1}+e^{X}\frac{\partial P_{1}}{\partial X}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial X})&\newln % +\rho\sigma v(e^{X}\frac{\partial P_{1}}{\partial v}+e^{X}\frac{\partial^2 P_{1}}{\partial X\partial v} -Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X\partial v})\newln % +\frac{1}{2}v\sigma^2(e^{X}\frac{\partial^2 P_{1}}{\partial v^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial v^2})&\newln % +[\kappa(\theta-v)-\lambda v] (e^{X}\frac{\partial P_{1}}{\partial v}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial v})&\newln % -r(e^{X}P_{1}-Ke^{-r(T-t)}P_{2})\newln % +(e^{X}\frac{\partial P_{1}}{\partial t}-rKe^{-r(T-t)}\partial P_{2}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial t}) &= 0\\ % e^{X}&\left[\frac{1}{2}v\frac{\partial^2 P_{1}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{1}}{\partial X\partial v} % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{1}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{1}}{\partial v}+(r+\frac{1}{2}v)\frac{\partial P_{1}}{\partial X}+\frac{\partial P_{1}}{\partial t}\right]\newln % -Ke^{-r(T-t)}\left[\frac{1}{2}v\frac{\partial^2 P_{2}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{2}}{\partial X\partial v}\parenthnewln % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{2}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{2}}{\partial v}+(r-\frac{1}{2}v)\frac{\partial P_{2}}{\partial X}+\frac{\partial P_{2}}{\partial t}\right] &= 0 \end{split} \end{eqnarray} I have put new lines within an equation using the \newln command. If the new line is within a set of parenthesis (the \left[ and \right]), then I use \parenthnewln. Remember that you can always add white space (blank lines need the % comment in equation environments) to make your work more legible.
 P: 7 thank you so much! this looks so nice. does it only work to one single equation? can it be used for multiple equations e.g proof?thanks
 P: 7 Fenn, I labeled the code \end{split}\label{eq:eu}\end{eqnarray} but the equation number disappears. I want it to be on the second formula.why is this so? the referencing works fine as the equation number shows
P: 7
Hi Fenn, I have tried on other LONG equations that I have. Unfortunately, not all worked out fine. Some were indented to half of the page and gone missing for the second half. I realize that this happens with multi equations where for example

\begin{eqnarray}
Eq 1 (Long) = Eq 2 (Long)
Eq 3 (Long) = Eq 4 (Long)
\end{eqnarray}

Hope you can help me with this problem. I have tons of equations to adjust. TQ so much

 Quote by Fenn Here's a quick tweaking of your markup, where I have used a modified version of these \newln and \parenthnewln commands that I suggested in an earlier post: $$\newcommand{\newln}{\\&\hspace{2em}} \newcommand{\parenthnewln}{\right.\newln\left.{}} \begin{eqnarray} \begin{split} \frac{1}{2}v&(e^{X}P_{1}+2e^{X}\frac{\partial P_{1}}{\partial X}+e^{X}\frac{\partial^2 P_{1}}{\partial X^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X^2})&\newln % +(r-\frac{1}{2}v)(e^{X}P_{1}+e^{X}\frac{\partial P_{1}}{\partial X}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial X})&\newln % +\rho\sigma v(e^{X}\frac{\partial P_{1}}{\partial v}+e^{X}\frac{\partial^2 P_{1}}{\partial X\partial v} -Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X\partial v})\newln % +\frac{1}{2}v\sigma^2(e^{X}\frac{\partial^2 P_{1}}{\partial v^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial v^2})&\newln % +[\kappa(\theta-v)-\lambda v] (e^{X}\frac{\partial P_{1}}{\partial v}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial v})&\newln % -r(e^{X}P_{1}-Ke^{-r(T-t)}P_{2})\newln % +(e^{X}\frac{\partial P_{1}}{\partial t}-rKe^{-r(T-t)}\partial P_{2}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial t}) &= 0\\ % e^{X}&\left[\frac{1}{2}v\frac{\partial^2 P_{1}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{1}}{\partial X\partial v} % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{1}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{1}}{\partial v}+(r+\frac{1}{2}v)\frac{\partial P_{1}}{\partial X}+\frac{\partial P_{1}}{\partial t}\right]\newln % -Ke^{-r(T-t)}\left[\frac{1}{2}v\frac{\partial^2 P_{2}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{2}}{\partial X\partial v}\parenthnewln % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{2}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{2}}{\partial v}+(r-\frac{1}{2}v)\frac{\partial P_{2}}{\partial X}+\frac{\partial P_{2}}{\partial t}\right] &= 0 \end{split} \end{eqnarray}$$ For some reason the [ tex ] markup does not appear to be working properly, so I have included the code as well. \newcommand{\newln}{\\&\hspace{2em}} \newcommand{\parenthnewln}{\right.\newln\left.{}} \begin{eqnarray} \begin{split} \frac{1}{2}v&(e^{X}P_{1}+2e^{X}\frac{\partial P_{1}}{\partial X}+e^{X}\frac{\partial^2 P_{1}}{\partial X^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X^2})&\newln % +(r-\frac{1}{2}v)(e^{X}P_{1}+e^{X}\frac{\partial P_{1}}{\partial X}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial X})&\newln % +\rho\sigma v(e^{X}\frac{\partial P_{1}}{\partial v}+e^{X}\frac{\partial^2 P_{1}}{\partial X\partial v} -Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial X\partial v})\newln % +\frac{1}{2}v\sigma^2(e^{X}\frac{\partial^2 P_{1}}{\partial v^2}-Ke^{-r(T-t)}\frac{\partial^2 P_{2}}{\partial v^2})&\newln % +[\kappa(\theta-v)-\lambda v] (e^{X}\frac{\partial P_{1}}{\partial v}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial v})&\newln % -r(e^{X}P_{1}-Ke^{-r(T-t)}P_{2})\newln % +(e^{X}\frac{\partial P_{1}}{\partial t}-rKe^{-r(T-t)}\partial P_{2}-Ke^{-r(T-t)}\frac{\partial P_{2}}{\partial t}) &= 0\\ % e^{X}&\left[\frac{1}{2}v\frac{\partial^2 P_{1}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{1}}{\partial X\partial v} % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{1}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{1}}{\partial v}+(r+\frac{1}{2}v)\frac{\partial P_{1}}{\partial X}+\frac{\partial P_{1}}{\partial t}\right]\newln % -Ke^{-r(T-t)}\left[\frac{1}{2}v\frac{\partial^2 P_{2}}{\partial X^2}+\rho\sigma v\frac{\partial^2 P_{2}}{\partial X\partial v}\parenthnewln % +\frac{1}{2}v\sigma^2\frac{\partial^2 P_{2}}{\partial v^2}\parenthnewln % +[\kappa(\theta-v)-\lambda v]\frac{\partial P_{2}}{\partial v}+(r-\frac{1}{2}v)\frac{\partial P_{2}}{\partial X}+\frac{\partial P_{2}}{\partial t}\right] &= 0 \end{split} \end{eqnarray} I have put new lines within an equation using the \newln command. If the new line is within a set of parenthesis (the \left[ and \right]), then I use \parenthnewln. Remember that you can always add white space (blank lines need the % comment in equation environments) to make your work more legible.
 P: 74 Hi sni, Working with equation formatting and layout in LaTeX can get very tedious if the equation is very long. I suggest you start with smaller equations and practice using the markup to do what you want. A very useful technique is to comment (%) out sections of equations while you're setting it up, and slowly removing the comment markers as you build it. When I posted my suggestion to your problem, I commented out all but the first line, checked to see what it looked like, and slowly introduced more of the equation as I became more familiar with its content, and the overall formatting use.
 P: 7 yes,i 've figured that now. thanks though for your advise. i really2 appreciate it.

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