i am trying to map archaeological finds with qgis. some of them have the same coordinates since they are from the same site or very close to each other. is it possible to automatically display the number of finds in a close range through a varying size of the symbol? so, the more datapairs i have in the same spot, the bigger the symbol gets? otherwise 10 finds just appear as one in the map because they are kind of on top of each other...
You can use the 'Point displacement' renderer for your point layer. Get the Layer Properties window up, click on the Styles tab and select Point Displacement from the drop-down list.
See image below for an example:
There are a few options you can tinker with but basically you end up with concentric rings radiating from the common location (in this example a red dot):
Is not exactly what you ask for, but i think that a heatmap is good choice for your case.
qgis has a heatmap plugin that can helps you.
One approach could be to create a polygon grid over your area of interest, with the grid cell size matching what you consider "close range" so that each site is covered by one cell. THis you can do with the "Vector grid" option under "Reasech tools". Then use the Points in Poly tool under "Analysis tools" to get a count of points in each polygon grid cell. Now stylize the polygon cells with a color ramp based on the PNTCNT attribute. HTH