COMETS 1.5. Handling of missing data

[steven-moore]

Several investigators have been trying to input missing data, which causes errors. All metabolites and subjectdata variables should be tested for this.

Possible fixes include: a) An improved tutorial b) Tests in the Data Input function c) Tests in the "Read datafile", or "Integrity check", or "getModel" functions.

Because this check could add some time, we could add this as an option, i.e. add a checkbox to test the variables, default is no test of the variables.

[ellatemprosa]

needs more thinking through

[ewymathe]

Goes with reading in data with rio package