I am very new at using GIS data and in particular QGIS (1.7.3) and I need some help to produce histograms regarding my data. I have a great number of data about an algae density collected in 8 sampling sites 4 times a year for 5 years. I would like to analyse them, underlining the differences in density, for each site, both among times and years but I don't know how to do this. I can create a layer for each considered year but I'm not able to image how to compare with histograms the density among years for each site. Can you please help me? I thank you in advance. Best regards Giovanni
You can try the QGIS plugin to analyse your data using R packages. The link above can give some tips:
Or you can export your data to one statistical software and run the analyses there. I'm still recommending R.