# Change TikZ's default coordinate system

In the TikZ manual I read that the default coordinate system's spacing is 1cm, so that (1,1) would be a vector going 1cm in x-direction and 1cm in y. In a diagram with a lot of nodes, that I am placing using the options such as above =of ..., this spacing is too much.

In order to change that, how can I change the coordinate system's default spacing?

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I have deleted my answer since I totally misread your question. Sorry for that. –  percusse Oct 9 '11 at 10:50
Not a problem. Can you explain why you misunderstood my question? That could help me formulating better questions in the future. –  Ingo Oct 9 '11 at 12:45
Actually it is a mistake on my side. I think you have formulated your question in a good way. It is the last sentence that made me think that you are looking for a change in the unit length of the axis which is the first part of Torbjorn's answer. –  percusse Oct 9 '11 at 19:35

You can change the coordinate system with x=<length> and y=<length> as options to a tikzpicture, e.g.

\begin{tikzpicture}[x=0.5cm,y=0.5cm]


however in your case you would probably rather change the node distance, as this defines the distance between nodes when using the above=of syntax:

\begin{tikzpicture}[node distance=0.5cm]


or

\begin{tikzpicture}[node distance=0.5cm and 0.5cm]


The difference between these two cases is illustrated in the TikZ/PGF manual (§16.5.3 Advanced Placement Options, pages 187-188, for v. 2.10).

You could also set this globally, by using \tikzset, i.e. add

\tikzset{node distance=0.5cm and 0.5cm}