Merge pull request #221 from JuliaAI/default-logger

Make the global `default_logger()` the default `logger` in `TunedModel(logger=...)`

Project.toml

@@ -1,7 +1,7 @@
 name = "MLJTuning"
 uuid = "03970b2e-30c4-11ea-3135-d1576263f10f"
 authors = ["Anthony D. Blaom <anthony.blaom@gmail.com>"]
-version = "0.8.7"
+version = "0.8.8"
 
 [deps]
 ComputationalResources = "ed09eef8-17a6-5b46-8889-db040fac31e3"
@@ -18,7 +18,7 @@ StatisticalMeasuresBase = "c062fc1d-0d66-479b-b6ac-8b44719de4cc"
 ComputationalResources = "0.3"
 Distributions = "0.22,0.23,0.24, 0.25"
 LatinHypercubeSampling = "1.7.2"
-MLJBase = "1.4"
+MLJBase = "1.5"
 ProgressMeter = "1.7.1"
 RecipesBase = "0.8,0.9,1"
 StatisticalMeasuresBase = "0.1.1"

src/tuned_models.jl

@@ -257,6 +257,10 @@ key | value
  regular [`PerformanceEvaluation`](@ref) objects to the history (accessed via the
  `:evaluation` key); the compact form excludes some fields to conserve memory.
 
+- `logger=default_logger()`: a logger for externally reporting model performance
+ evaluations, such as an `MLJFlow.Logger` instance. On startup,
+ `default_logger()=nothing`; use `default_logger(logger)` to set a global logger. 
+
 """
 function TunedModel(
  args...;
@@ -281,7 +285,7 @@ function TunedModel(
  check_measure=true,
  cache=true,
  compact_history=true,
- logger=nothing
+ logger=MLJBase.default_logger()
  )
 
  # user can specify model as argument instead of kwarg:

test/tuned_models.jl

@@ -526,4 +526,29 @@ end
  @test first(evaluations) isa MLJBase.PerformanceEvaluation
 end
 
+struct DummyLogger
+ buffer
+end
+
+MLJBase.log_evaluation(logger::DummyLogger, performance_evaluation) =
+ write(logger.buffer, performance_evaluation.measurement[1])
+
+@testset "default logger" begin
+ buffer = IOBuffer()
+ logger = DummyLogger(buffer)
+ default_logger(logger)
+ model1 = KNNRegressor(K=5)
+ model2 = KNNRegressor(K=3)
+ tmodel = TunedModel(models=[model1, model2], measure=l2)
+ mach = machine(tmodel, make_regression(10)...)
+ fit!(mach, verbosity=0)
+ seekstart(buffer)
+ @test all(report(mach).history) do entry
+ logger_measurement = read(buffer, Float64)
+ logger_measurement == entry.evaluation.measurement[1]
+ end
+ default_logger(nothing)
+ close(buffer)
+end
+
 true