A PatternMonitor reads the firing rates of subpopulations of neurons in a NeuronGroup as specified in a pattern file and writes multicolumn text output to a pact file.

PatternMonitor * patmon 
   = new PatternMonitor(neurons_e,
                        outputfile,
                        patternfile,
                        100);

This snipped of code defines a PatternMonitor patmon which is associated with a NeuronGroup neurons_e. Its output is written to outputfile and as a third argument it expects a pat file which specifies one or multiple subpopulations of neurons within neurons_e. The number 100 specifies the maximum number of patterns to load from patternfile. If it is omitted PatternMonitor will only read the first 10 to not clutter the output file with too many columns. The constructor accepts one additional parameter which controls the sampling interval which per default is set to 100ms.