What does "ds_scale_mean" refer to?

[jack1234lee]

I'm currently inquiring about what "ds_scale_mean" in loader.py specifically refers to. I've come across this term while working with the loader.py file, and it's not entirely clear to me what it represents. Could you please provide a detailed explanation regarding its meaning and the role it plays within the context of this particular file? Thank you very much.

[tbennun]

Hi @jack1234lee, ds_scale_mean refers to the mean value across the dataset, which is used to normalize the actual values (which vary quite a bit, even across pressure levels) into something that is more palatable to a machine learning model. These values (mean, std for standard deviation) are typically very costly to compute on large datasets, so they are precomputed and stored into files.

Hope this helps!

[jack1234lee]

Thank you for your answer, but I still have some doubts. There is a class class ENS10GridDataset(Dataset) in the loder.py file. Now I know that mean and std are mean and standard deviation respectively. However, it is not clear what difference will be made if scale is added (such as ds_mean and ds_scale_mean, ds_std and ds_scale_std), I hope you can answer it for me, thank you very much!