floats
I am working with texshop on Mac and because of an upgrade to El Capitan,
I had to reinstall tex live. Now I have a problem with older files where
figures are inserted. I get the message
LaTeX Error: Unknown float option `,'.
I do not even know what this is, let alone how to fix it. The figure does
appear, but is there something else in another place in the file that
went wrong? I am typesetting a whole book and this problems appears with
some, but not all of the figures.
There are several methods to deal with float placement control, see the comments to the question, e.g.:
float with placement specifier H sets the floats right "here" without floating.\clearpage before \section{Appendix} forces the floats to be output and starts a new page.\FloatBarrier of package placeins right before \section{Appendix} stops tables from floating past the appendix title.table) with \captionof{table} of package capt-of or the more powerful caption.(It is a little bit difficult to say for sure, but I think I know why this happens. At least partly.)
There are two problems relating to the paragraph settings of the paragraphs containing the floats that can produce additional whitespace.
If you look at the LaTeX source of one of the figures you'll see something like
\noindent
\begin{figure}
...
The problem here is the \noindent which comes from the paragraph settings in LyX. What you should do is right click just outside each figure, choose Paragraph settings, and check the box for Indent paragraph. If you have the source view open you'll see that the \noindent disappears when you click OK/Apply.
For two of the figures (second and third last in your example) the alignment of the paragraph with the figure is set to Center, and if you look in the code you see something like
\begin{center}
\begin{figure}
...
\end{figure}
\par\end{center}
The surrounding center environment should be removed, by setting the paragraph alignment to Paragraphs default (justified).
To demonstrate how this can give extra whitespace, consider the following LaTeX code, the output is shown below it:
\documentclass{article}
\begin{document}
Some words.
\noindent
More words.
\noindent \begin{figure}
This is a figure.
\end{figure}
Words
\begin{center}
\begin{figure}
Another figure
\end{figure}
\end{center}
More.
\end{document}
One or more empty line(s) signifies that a new paragraph should start, and new paragraphs are by default indicated by indentation. \noindent lets you remove this indentation for a single paragraph.
Now in the code above, the first \noindent does nothing, because there isn't anything there that can start a new paragraph. So you see that there is no extra space between Some words and More words. In the second case however, the \begin{figure} causes a new paragraph to start, but the only thing in it -- the figure itself -- floats away, so you're left with an empty paragraph.
Further, the center environment adds some verticl whitespace before and after, and when the only thing inside it is a figure that floats away, you're left with just that vertical whitespace.
Best Answer
You have something like
which was always an error but in older latex releases silently ignored
Now it generates an error that
,is not known, and should be deleted.the worst case was if you had
as previously this would not generate an error but it prevents the float being placed anywhere until it is flushed out at the end of the document or by
\clearpage