# Strange Arrow length

I wish my arrows have the same size. For example, I can not explain why the two vertical arrows coming out of the vertex "a" have different sizes.

\documentclass{article}
\usepackage{tikz-cd}
\usepackage{amsmath}
\begin{document}
$$\begin{tikzcd} [column sep=small , row sep=small ] &&& \bullet \ar{dl} \ar{dr}&&& \\ && \bullet \ar{dl}& \vdots \ar{u}& \bullet \ar{dr}&& \\ & \iddots \ar{dl}&& \bullet \ar{u}&& \ddots \ar{dr}& \\ \bullet \ar{r}& \dotsc \ar{r}& \bullet \ar{r}& a \ar{u} \ar{d}& \bullet \ar{l}& \dotsc \ar{l}& \bullet \ar{l}\\ & \ddots \ar{ul}&& \bullet \ar{d}&& \iddots \ar{ur}& \\ && \bullet \ar{ul}& \vdots \ar{d}& \bullet \ar{ur}&& \\ &&& \bullet \ar{ul} \ar{ur}&&& \end{tikzcd}$$
\end{document}


• Welcome to TeX.SX! Your problem is the different size of the cells. You could make them all the same size with phantoms or struts. Off topic: tex.stackexchange.com/q/503 Please make your code compilable! mathdots is missing. May 8, 2015 at 6:52

You will need to set the column and row distance in respect to the cells centre. I adapted some of the dots for you. I stretched the whole thing a bit in order to get the same angle as for the \ddots. If you want a symmetrical diagram, you will have to rotate those dots a bit.

% arara: pdflatex

\documentclass{article}
\usepackage{tikz-cd}
\usepackage{mathtools}
\usepackage{mathdots}
\makeatletter
\DeclareRobustCommand{\rvdots}{%
\vbox{
\baselineskip4\p@\lineskiplimit\z@
\kern-\p@
\hbox{.}\hbox{.}\hbox{.}
}}
\makeatother

\begin{document}
$\begin{tikzcd} [column sep={1.32cm,between origins} , row sep={1cm,between origins} ] &&& \bullet \ar{dl} \ar{dr}&&& \\ && \bullet \ar{dl}& \rvdots \ar{u}& \bullet \ar{dr}&& \\ & \iddots \ar{dl}&& \bullet \ar{u}&& \ddots \ar{dr}& \\ \bullet \ar{r}& \cdots \ar{r}& \bullet \ar{r}& a \ar{u} \ar{d}& \bullet \ar{l}& \cdots \ar{l}& \bullet \ar{l}\\ & \ddots \ar{ul}&& \bullet \ar{d}&& \iddots \ar{ur}& \\ && \bullet \ar{ul}& \rvdots \ar{d}& \bullet \ar{ur}&& \\ &&& \bullet \ar{ul} \ar{ur}&&& \end{tikzcd}$
\end{document}


You may need less tweaking if you use the following approach:

% arara: pdflatex

\documentclass{article}
\usepackage{tikz-cd}

\begin{document}
$\begin{tikzcd} [column sep={1cm,between origins} , row sep={1cm,between origins} ] & & & \bullet \ar{dl} \ar{dr} & & & \\ & & \bullet \ar{ddll}[description,sloped]{\dots} & & \bullet \ar{ddrr}[description,sloped]{\dots} & & \\ & & & \bullet \ar{uu}[description,sloped]{\dots} & & & \\ \bullet \ar{rr}[description]{\dots} & & \bullet \ar{r} & a \ar{u} \ar{d}& \bullet \ar{l} & & \bullet \ar{ll}[description]{\dots}\\ & \ar{ul}&& \bullet \ar{dd}[description,sloped]{\dots} & & & \\ & & \bullet \ar{uull}[description,sloped]{\dots} & & \bullet \ar{uurr}[description,sloped]{\dots} & & \\ & & & \bullet \ar{ul} \ar{ur} & & & \end{tikzcd}$
\end{document}