After you have defined all reactions
that make up your model, you could go ahead and do some calculations with your model. For some of the task this is fine since they show you the results in a separate results dialog and it might not be necessary to store those results into a file. For other tasks, like e.g. a time course, it is very likely that you want to store the resulting trajectory in a file or plot the result for visual inspection. So if you want COPASI to store the results or do a plot of them, you have to define either a report and associate it with a file or define a plot. (In the section we will also offer an alternative, albeit less flexible, way for storing the results of a time course simulation.)
COPASI already has a list of predefined reports suitable for some of the calculation task. These are described in the next paragraph. If you want to create your own plots or reports you can either use the output assistant (the easy way) or you can define the output manually (the flexible way), as described in the section.