LyX: set width of image to 100% of page width

Question

When I insert an image into LyX and set it to 100% page width, its left side is not at the farthest most edge of the left page. Instead it starts where the text margin is, and since it's too large to display, it cuts off on the right. Is there a way to set a different margin for figures than that of the text?

Answer 1

The horizontal image shift is due to the paragraph indent if you don't place the image inside a figure environment. To avoid this without inserting a figure environment, insert an ERT (or Ctrl+L) just before the image that contains \noindent. This removes the paragraph indent so that the image will fit within the text block.

Answer 2

To make your graphics span the full paper widht, you need a negative \hskip to compensate for the left margin. Hence, add something like this in an ERT box directly before your graphics:

\hskip\dimexpr-\hoffset-1in-\oddsidemargin-\leftskip\relax

This assumes, however, that the float will be placed on an odd page. Depending on the document class and layout options, the page margins on odd and even pages may differ. To take this into accout requires a somewhat bigger effort. Add the following to your preamble (Document->Settings->LaTeX Preamble):

\usepackage{changepage}
\strictpagecheck

\newlength{\totalleftmargin}
\newcommand{\calctotalleftmargin}{%
  \setlength{\totalleftmargin}{\dimexpr+\hoffset+1in+\leftskip}%
  \checkoddpage%
  \addtolength{\totalleftmargin}{\ifoddpage\oddsidemargin\else\evensidemargin\fi}%
}

The ERT box directly before your graphics does then become:

\calctotalleftmargin
\hskip-\totalleftmargin\relax