Better looking equations

Question

I am trying to find a way to make the equations that appear in this text a bit more better looking...

\documentclass{article}
\usepackage{amsmath, amssymb}
\usepackage{relsize}

\begin{document}

\begin{equation}
    N_\text{c}(i) = \dfrac{N_\text{o}(i)}{1 - \mathlarger{‎‎\sum}_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b} - N_\text{o}(i)/2N_\text{b}}\label{eq:Bollinger}
\end{equation}

\begin{equation}
    N_\text{c}(i) = -N_\text{b}\ln{\left(1-\dfrac{N_\text{o}(i)/N_\text{b}}{1-\mathlarger{\sum}_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b}}\right)}
\end{equation}

\begin{equation}
    N_\text{c}(i) = -N_\text{b}\dfrac{\ln{\left(1-\dfrac{N_\text{o}(i)/N_\text{b}}{1-\mathlarger{\sum}_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b}}\right)}}{1-\sigma\tanh\left(\sigma\mathlarger{\sum}_{j=i_0}^{i-1}N_\text{c}(j)/N_\text{b}\right)}
\end{equation}

\end{document}

Any idea on how to make them look more beautiful?

@TeXnician Thank you very much for your comment! What do you mean rewrite them? — Thanos, Nov 03 '17 at 14:46
Well, I just mean that the equations as they are written do not look that bad (actually if that's your real text width I think it's pretty good then). But they look monstrous, because of how they are written (much white space etc.) So the most effective way of making them "beautiful" would probably be to use some other form, but I'm no mathematician, so can't judge if that would be a good idea. — TeXnician, Nov 03 '17 at 14:50
@TeXnician Exaclty this white space is the problem, but I would prefer to keep the form as is, since it makes it more comprehensive in the text... — Thanos, Nov 03 '17 at 14:53
The white space is caused by \left and \right, if I remember correctly, because they calculate the box height and try to keep stuff like the - or the fraction's line at half of the height. That may have the unwanted side effect of bad spacing. — TeXnician, Nov 03 '17 at 15:02
The thing is that without \mathlarger the sums look ugly... — Thanos, Nov 03 '17 at 15:04
Okay, one could use \limits instead, but that saves only very little. — TeXnician, Nov 03 '17 at 15:19
See https://tex.stackexchange.com/questions/397992/blank-space-with-left-and-right — Ulrike Fischer, Nov 03 '17 at 15:21
never have a blank line above a display equation (the output tex produces in that case always has a spurious white line) you probably just want _{c} or\mathrm{c}rather than\text{c}in subscripts, I would not use\mathlargeras you can see it is spoiling the alignment of the summation, and use\biglnot \left\right` to stop the over-sized brackets — David Carlisle, Nov 03 '17 at 15:48
Most of your extra whitespace is caused by including the sums in the fractions. If I was in your shoes, I would define something like S = \sum_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b} in the line before the equation, and then rewrite the equations in terms of S. — Michael Seifert, Nov 03 '17 at 19:17

score 7 · Answer 1 · answered Nov 03 '17 at 16:05

Avoid having blank lines before display mat, or consecutive display math (TeX can not really handle either in a sane way) and keep control over the delimiters by avoiding \left\right I guessed you want to keep the \limits setting of the summation so I kept the normal summation (which has better vertical alignment) and made a larger but still fixed bracket size to cope with the large numerator.

\documentclass{article}
\usepackage{amsmath, amssymb}
\makeatletter
\def\Biggg#1{{\hbox{$\left#1\vbox to21\p@{}\right.\n@space$}}}
\def\Bigggl{\mathopen\Biggg}
\def\Bigggm{\mathrel\Biggg}
\def\Bigggr{\mathclose\Biggg}
\makeatother

\begin{document}

align (or gather if no alignement)
\begin{align}
    N_{\mathrm{c}}(i) &= \frac{N_\text{o}(i)}{1 - ‎‎\sum\limits_{j=i_0}^{i-1}N_\text{o}(j)/N_{\mathrm{b}} - N_\text{o}(i)/2N_{\mathrm{b}}}\label{eq:Bollinger}
\\[\jot]
    N_{\mathrm{c}}(i) &= -N_{\mathrm{b}}\ln{\Biggl(1-\frac{N_\text{o}(i)/N_{\mathrm{b}}}{1-\sum\limits_{j=i_0}^{i-1}N_\text{o}(j)/N_{\mathrm{b}}}\Biggr)}
\\[\jot]
    N_{\mathrm{c}}(i) &= -N_{\mathrm{b}}\frac{\ln{\Bigggl(1-\dfrac{N_\text{o}(i)/N_{\mathrm{b}}}{1-\sum\limits_{j=i_0}^{i-1}N_\text{o}(j)/N_{\mathrm{b}}}\Bigggr)}}{1-\sigma\tanh\left(\sigma\sum\limits_{j=i_0}^{i-1}N_{\mathrm{c}}(j)/N_{\mathrm{b}}\right)}
\end{align}

\end{document}

score 6 · Answer 2 · answered Nov 03 '17 at 16:32

Instead of \mathlarger{\sum}, just make sure the numerators and denominators are in display-style math. To avoid excessively large parentheses, use \sum\nolimits. Use \Biggl( and \Biggr) for the larger parentheses in rows 2 and 3, and use \Bigl( and \Bigr) for the parentheses in the denominator of row 3. Finally, I would use \mathrm rather than \text to render the items c, i and o, to get the math-specific spacing.

\documentclass{article}
\usepackage{amsmath, amssymb}
\newcommand\ddfrac[2]{\dfrac{\displaystyle #1}{\displaystyle #2}}

\begin{document}

\begin{align}
N_{\mathrm{c}}(i) 
&= \ddfrac{N_{\mathrm{o}}(i)}{1 - \sum\nolimits_{j=i^{}_0}^{i-1}N_{\mathrm{o}}(j)/N_{\mathrm{b}} - N_{\mathrm{o}}(i)/2N_{\mathrm{b}}}\label{eq:Bollinger}\\[2ex]
N_{\mathrm{c}}(i) 
&= -N_{\mathrm{b}}\ln\Biggl(1-\ddfrac{N_{\mathrm{o}}(i)/N_{\mathrm{b}}}{1-\sum\nolimits_{j=i^{}_0}^{i-1}N_{\mathrm{o}}(j)/N_{\mathrm{b}}}\Biggr) \\[2ex]
N_{\mathrm{c}}(i) 
&= -N_{\mathrm{b}}\,\ddfrac{\ln\Biggl(1-\ddfrac{N_{\mathrm{o}}(i)/N_{\mathrm{b}}}{1-\sum\nolimits_{j=i^{}_0}^{i-1}N_{\mathrm{o}}(j)/N_{\mathrm{b}}}\Biggr)}{1-\sigma\tanh\Bigl(\sigma\sum\nolimits_{j=i^{}_0}^{i-1}N_{\mathrm{c}}(j)/N_{\mathrm{b}}\Bigr)}
\end{align}

\end{document}

Phelype Oleinik · Answer 3 · 2017-11-03T21:05:11.900

If you must keep the equation as it is and just remove the excess space (nasty thing to do but...) you can use fixit from this solution:

\fixit[<mathstyle>]{<left-delim>}{<content>}{<right-delim>}

The command definition is:

\usepackage{amsmath}
\newcommand\fixit[4][\displaystyle]{
  \setbox0=\hbox{$#1#3$}
  \setbox2=\hbox{$\vcenter{\copy0}$}
  \raisebox{\dimexpr\ht0-\ht2}{$#1\left#2\copy2\right#4$}
}

MWE for your case:

\documentclass{article}
\usepackage{amsmath, amssymb}
\usepackage{relsize}
\newcommand\fixit[4][\displaystyle]{
  \setbox0=\hbox{$#1#3$}
  \setbox2=\hbox{$\vcenter{\copy0}$}
  \raisebox{\dimexpr\ht0-\ht2}{$#1\left#2\copy2\right#4$}
}
\begin{document}

\begin{equation}
    N_\text{c}(i) = -N_\text{b}\ln{\fixit{(}{1-\dfrac{N_\text{o}(i)/N_\text{b}}{1-\mathlarger{\sum}_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b}}}{)}}
\end{equation}

\end{document}

The result:

score 4 · Answer 4 · answered Nov 03 '17 at 14:59

One way to reduce the white space (I do not think that the following is really more beautiful) is to make your \mathlarger small again.

The white space (AFAIK) results from the computations of \left etc. which stupidly scales up the parenthesis. See e.g. "(" or "\left(" parentheses?

\documentclass{article}
\usepackage{amsmath, amssymb}
\usepackage{relsize}

\begin{document}

\begin{equation}
    N_\text{c}(i) = \frac{N_\text{o}(i)}{1 - ‎‎\sum_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b} - N_\text{o}(i)/2N_\text{b}}\label{eq:Bollinger}
\end{equation}

\begin{equation}
    N_\text{c}(i) = -N_\text{b}\ln{\Biggl(1-\frac{N_\text{o}(i)/N_\text{b}}{1-\sum_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b}}\Biggr)}
\end{equation}

\begin{equation}
    N_\text{c}(i) = -N_\text{b}\frac{\ln{\Biggl(1-\dfrac{N_\text{o}(i)/N_\text{b}}{1-\sum_{j=i_0}^{i-1}N_\text{o}(j)/N_\text{b}}\Biggr)}}{1-\sigma\tanh\left(\sigma\sum_{j=i_0}^{i-1}N_\text{c}(j)/N_\text{b}\right)}
\end{equation}

\end{document}

Better looking equations

4 Answers4

The result:

Linked