General ⇒ Text Spacement Problems with Equations

[Cham]

I'm experiencing a problem with spacement above many displayed equations (not all of them).

I'm currently using a solution which works, but it's a kind of "hack" and it's certainly not in the spirit of LaTeX. My solution is annoying since I can't predict the result, if I edit the text above an equation. I frequently have to "hack" the code after I see the output, so this is certainly NOT the way to go with LaTeX.

Here's a complete compilable example.

Code: Select all

\documentclass[12pt,letterpaper]{article}
\usepackage[T1]{fontenc}
\usepackage{setspace}
\setstretch{1.1}
\usepackage{anysize}
\marginsize{1.5in}{1in}{0.5in}{0.5in}

\newcommand*{\topless}{\setlength{\abovedisplayskip}{0pt}}
\newcommand*{\topmore}{\setlength{\abovedisplayskip}{12pt}}

\begin{document}

\section{Code with spacement problems}
Bla bla bla bla bla bla bla blabla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla :
	\begin{equation}
		A + B - C = 0.
	\end{equation}
Bla bla blabla bla bla blabla bla bla bla
	\begin{equation}
		D + E = F.
	\end{equation}
bla bla bla bla :
	\begin{equation}
		P - G + H = K - L,
	\end{equation}
bla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla bla.
	\begin{equation}
		A + B - C + G - H = J - K.
	\end{equation}
bla bla bla blabla bla bla
	\begin{equation}
		A + B - C + G - H = J - K.
	\end{equation}
bla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla
	\begin{equation}
		C + D - H = FG - HK
	\end{equation}

\section{Same code with "hacks"}
Bla bla bla bla bla bla bla blabla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla :
\topless
	\begin{equation}
		A + B - C = 0.
	\end{equation}
Bla bla blabla bla bla blabla bla bla bla
\topmore
	\begin{equation}
		D + E = F.
	\end{equation}
bla bla bla bla :
	\begin{equation}
		P - G + H = K - L,
	\end{equation}
bla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla blabla bla bla bla.
	\begin{equation}
		A + B - C + G - H = J - K.
	\end{equation}
bla bla bla blabla bla bla
\topless
	\begin{equation}
		A + B - C + G - H = J - K.
	\end{equation}
bla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla bla blabla
	\begin{equation}
		C + D - H = FG - HK
	\end{equation}

\end{document}

Here's a preview of part of the output (with colorized indicators added by hand).

spacements.jpg (97.6 KiB) Viewed 5354 times

The first section isn't using any "hack" and the problems are showing there (red cross). The second section is using some hacks to solve the issue (see both macros I defined in the preamble).

Apparently, the problem is caused by the following commands in the preamble :

Code: Select all

\usepackage{setspace}
\setstretch{1.1}
\usepackage{anysize}
\marginsize{1.5in}{1in}{0.5in}{0.5in}

Of course, if I change any of these commands, the output is completely different!
I need those margin sizes and the 1.1 stretch between text lines (because of some intext equations). The spacements should be as shown in the second section.

So what should I do to solve the issue, without using a special macro before some equations ?

[Cham]

No idea on this ?

I suspect I should use the geometry package, instead of anysize, but I don't know yet how to setup the margins to get exactly what I have with anysize.

[cgnieder]

I suspect I should use the geometry package, instead of anysize, but I don't know yet how to setup the margins to get exactly what I have with anysize.

Doesn't

Code: Select all

\usepackage{geometry}
\geometry{left=1.5in,right=1in,top=.5in,bottom=.5in}

do it?

Regards

[Cham]

Yes, I just found it :

Code: Select all

\usepackage[total={6in,10in},left=1.5in,top=0.5in,includehead,includefoot]{geometry}

But it doesn't solve the spacement problem with the displayed equations (subject of this topic).

Any idea ?

[cgnieder]

Well, the vertical space before a displayed equation is determined by \abovedisplayskip or \abovedisplayshortskip, respectively. TeX does some calculation depending on (roughly) \displaywidth (the width of the display equation) and \predisplaysize (the width of the last line before the displayed equation). What you could do to interfere with this calculation is shorten the \predisplaysize at the beginning of a displayed equation by, e.g., saying

Code: Select all

\everydisplay{\predisplaysize=\dimexpr\predisplaysize-2em\relax}

(you should probably play with the 2em to find a value that suits your wishes).

Regards

[Cham]

Thanks for this suggestion. It appears to work on my test file, but it's also changing the spacement between the sction title and the following text. I'm not sure this is ok yet.

[cgnieder]

it's also changing the spacement between the sction title and the following text.

This is quite impossible unless the definition of the sectioning commands has been changed in some weird way or the section titles are followed directly by a displayed equation (which also seems strange to me). Do you have a minimal working example that shows this behaviour?

[Cham]

I applied your suggestion to the previous example I gave above, to which I added these packages :

Code: Select all

\usepackage[french]{babel}
\usepackage{microtype}

EDIT : However, on my main (large) document, it appears to have no effect on the spacement between the section title and its text below it.

[cgnieder]

I see no changes with these packages (except for the paragraph indent, but that is \usepackage[french]{babel}'s fault and has nothing to do with \predisplaysize).

[Cham]

I'm testing further your suggestion on my main document. Let's see...