Validation of Graphical Output

If the software being validated creates a graph (xy scatter plot or bar chart) do they need to be validated? Would a check of a few points on the graph be sufficient to say it’s correct?

Yes the graphs would have to be tested if they provide infomation that forms part of a regulatory decision or has impact on the product.

The degree of testing is up to you but I would treat it as if you were validating reports from an application.