Comparing data and theory

For a tutorial on how to do a data-theory comparison, see here.

The name of the data-theory comparison tool is plot_fancy. You can see what parameters in the runcard influence it by typing:

validphys --help plot_fancy

The basic inputs are a dataset and one or more PDFs. The way a dataset is to be plotted is controlled by one or more PLOTTING files in the commondata format. These are simple YAML files and ideally each dataset should have them. It is possible to specify how to transform the kinematics stored in the commondata, what to use as x-axis or how to group the plots. The format is described in detail in Plotting format specification. The plotting specifications are supported by small amounts of Python (defining the various transformations), which are declared in the validphys.plotoptions package.

Note that PLOTTING files are considered part of nnpdfcpp, and as such they are assumed to be correct, so in principle they have no guarantee of failing early with a good error message. However, you can set check_plotting: True in the input configurations to cause the PLOTTING files to be processed as soon as the dataset is loaded. This can be useful while debugging the plotting files, but might cause a noticeable delay to the startup (due to loading datasets and fktables). This will warn the user of missing plotting files and produce nice early error messages if the configuration is not processed correctly.