Custom variables

[doc-l]

User should be able to create a variable "Z=X*Y" and plot for example Z against A.

Expert should be able to define these variables as well over all datasets. For example all datasets have the observable dark matter mass (M) and dark matter scattering probability (P) and we want to be able to define the constrain by detector limits. For example: P > 0.1 when M < 100, and P < 0.01 when M > 100 (these limits can be dependent on all variables)

Because these limits can change at any time and need to be up to date, these values cannot be part of the dataset. But maybe it is possible to put these computed variables in a text file and upload it on the server