Default value of sigmoid parameter for LightGBM

[mjmckp]

The default value of the sigmoid parameter for LightGBM is 1, however in the ML.Net wrapper it is hardwired to 0.5:

machinelearning/src/Microsoft.ML.LightGBM/LightGbmArguments.cs

Line 404 in f9d3973

res["sigmoid"] = "0.5";

Why is this the case? Shouldn't this parameter either be 1 or exposed on the ML.Net API instead?

[codemzs]

@guolinke were the default values updated recently? I can update this to 1 on ML.NET but just wanted to check.

[guolinke]

It is 1 in Lightgbm side.

[codemzs]

@guolinke Please take a look at the PR #667