# tex input or include another tex file

In a tex file, I need to draw a system diagram, so I put it in a separate tex like diagram.tex:

\documentclass[tikz]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw (0,0) -- (1,1);
\end{tikzpicture}
\end{document}


and then in main.tex:

\documentclass[10pt, a4paper]{article}
\usepackage[UTF8]{ctex}
\begin{document}
\section{sectionA}
\include{diagram} % I also tried input the same error. I wish diagram.tex figure could be inserted at this place.
\subsection{subsectionA}
\section{sectionB}
\end{document}


besides: running diagram.tex alone in latex gives:

! LaTeX Error: File standalone.cls' not found.Type X to quit or <RETURN> to proceed,or enter new name. (Default extension: cls)Enter file name:! Emergency stop.<read > \usepackage


So the question would be how to insert a standalone tex file? And is it possible to run a standalone tex alone? I am also studying tikz, while demos I found are mostly using standalone.

• I think the answer is in post : tex.stackexchange.com/questions/32127/standalone-tikz-pictures – Stan Feb 7 '18 at 7:18
• it is possible (but unnecessarily complicated) to make that work but it is much simpler to just have the tikzpicture in a separate file (no \documentclass etc) then you can simply \input it. – David Carlisle Feb 7 '18 at 7:48
• @DavidCarlisle make what work but complicated? – Tiina Feb 7 '18 at 8:16

• \documentclass[tikz]{standalone} load tikz, so it is not need to load it again with \usepackage{tikz}.

• in main document you need to load

• standalone for stripping out preamble in your diagra file
• tikz with necessary tikz libraries

i.e. all packages used in included document.

\documentclass[tikz]{standalone}

\begin{document}
\begin{tikzpicture}
\draw (0,0) -- (1,1);
\end{tikzpicture}
\end{document}


and

\documentclass[10pt, a4paper]{article}
\usepackage[UTF8]{ctex}

• are you suggesting using input instead of include – Tiina Feb 7 '18 at 8:38
• @Tiina, yes. i assume, that included file should not start on new page (this happens with \include`). – Zarko Feb 7 '18 at 8:43