# How to make a complicated arrow diagram?

I am trying to create a diagram with LaTeX as in the picture. The arrows are [Rightarrow] and [Leftarrow].

\begin{displaymath}
\xymatrix{
& & SCoS \ar[dll] \ar[d] \ar[drr] & & \\
CoS \ar[drr] \ar[rr] & & NS & & SCS \ar[dll] \ar[ddl] \\
& & CS \ar[dd] & & \\ & & & PO \ar[dl] & \\
& & wPO & &
}
\end{displaymath}

• welcome to tex.sx. there are several packages that might be helpful: tikz-cd and xypic come to mind. if you have a tex live installation, you should be able to access the documentation by asking for texdoc <package name>'. Nov 3 '17 at 12:53
• Welcome to TeX.SX! The short answer is that, yes, this is easy to do but I have to warn you that questions of the form "Please draw this for me", which show no effort on the part of OP, often don't get answered. You will get more help if you post some code showing what you have tried and give a minimal working example. A quick search on TeX.SX for drawing functions (with tikz or pstricks) will give you an idea of where to start.
– user30471
Nov 3 '17 at 14:28
• Barbara and Andrew, thanks for your answers. I have such a code (below). This diagram does the job. However, I want arrows to be in the form [\Rightarrow] and [\Leftarrow]. When I insert \Leftarrow , Latex gives an error. Do you have any suggestions ? Nov 3 '17 at 19:26
• \begin{displaymath} \xymatrix{ & & SCoS \ar[dll] \ar[d] \ar[drr] & & \\ CoS \ar[drr] \ar[rr] & & NS & & SCS \ar[dll] \ar[ddl] \\ & & CS \ar[dd] & & \\ & & & PO \ar[dl] & \\ & & wPO & & } \end{displaymath} Nov 3 '17 at 19:26
• @Sechkin Next time add your MWE to your question, not in a comment (I've done it for you now). Moreover, if you want to reply to someone use @ followed by the user name, otherwise the user won't be notified (you can reply only to one user at the time). Nov 4 '17 at 5:13

You could it easily with tikz-cd package.

Since your arrows are all Rightarrow (looking them from the starting point to the end point), I've put [arrows=Rightarrow] as an option of the tikzcd environment, otherwise you could put Rightarrow (or Leftarrow) as an option of \ar, for example \ar[Rightarrow, d].

Off-topic: I've used \text for the variables and adjusted the spacing between rows and columns of the matrix with some [...] after & and \\.

\documentclass{article}
\usepackage{tikz-cd}
\usepackage{amsmath}
\begin{document}
\begin{displaymath}
\begin{tikzcd}[arrows=Rightarrow]
&[10pt] & \text{SCoS} \ar[dll] \ar[d] \ar[drr] & & \\
\text{CoS} \ar[drr] \ar[rr]\ar[rrddd] & & \text{NS} & & \text{SCS} \ar[dll] \ar[ddl] \ar [ll]\\
& & \text{CS} \ar[dd] & & \\[-3ex]
& & & \text{PO} \ar[dl] & \\[4ex]
& & \text{wPO} & &
\end{tikzcd}
\end{displaymath}
\end{document}


Nowadays I'd use tikz-cd, but with Xy-pic it's possible too.

\documentclass{article}
\usepackage[all,cmtip]{xy}

\begin{document}

\begin{displaymath}
\xymatrix@R-2ex{
& & SCoS \ar@{=>}[dll] \ar@{=>}[d] \ar@{=>}[drr] & & \\
CoS \ar@{=>}[drr] \ar@{=>}[rr] \ar@{=>}[dddrr] & & NS
& & SCS \ar@{=>}[ll] \ar@{=>}[dll] \ar@{=>}[ddl] \\
& & CS \ar@{=>}[dd] & & \\ & & & PO \ar@{=>}[dl] & \\
& & wPO & &
}
\end{displaymath}

\end{document}
`