Im a newbie to TikZ, so this question may seem stupid. Im a looking at a facility location problem in the plane where I have generated some data points consisting of (x,y)-coordinates for each customer node and each facility node. In the literature, customers nodes are usually marked by a circular dot so I have used the notation
\draw [fill] (x,y) circle [radius=0.05];
for some point specified by (x,y).
The facility nodes are usually marked with a small square. But how do I create a square centered at the point (x,y)? I have looked at rectangle function. But as I have the center point, this approach does not seem to be the right way to go. Can anyone help me here?