Add a global default verbosity

docs/src/anatomy_of_an_implementation.md

@@ -106,7 +106,7 @@ Note that we also include `learner` in the struct, for it must be possible to re
 The core implementation of `fit` looks like this:
 
 ```@example anatomy
-function LearnAPI.fit(learner::Ridge, data; verbosity=1)
+function LearnAPI.fit(learner::Ridge, data; verbosity=LearnAPI.default_verbosity())
 
     X, y = data
 
@@ -397,7 +397,7 @@ methods - one to handle "regular" input, and one to handle the pre-processed dat
 (observations) which appears first below:
 
 ```@example anatomy2
-function LearnAPI.fit(learner::Ridge, observations::RidgeFitObs; verbosity=1)
+function LearnAPI.fit(learner::Ridge, observations::RidgeFitObs; verbosity=LearnAPI.default_verbosity())
 
     lambda = learner.lambda
 

docs/src/fit_update.md

@@ -3,8 +3,8 @@
 ### Training
 
 ```julia
-fit(learner, data; verbosity=1) -> model
-fit(learner; verbosity=1) -> static_model 
+fit(learner, data; verbosity=LearnAPI.default_verbosity()) -> model
+fit(learner; verbosity=LearnAPI.default_verbosity()) -> static_model 
 ```
 
 A "static" algorithm is one that does not generalize to new observations (e.g., some
@@ -15,8 +15,8 @@ clustering algorithms); there is no training data and the algorithm is executed
 ### Updating
 
 ```
-update(model, data; verbosity=1, param1=new_value1, param2=new_value2, ...) -> updated_model
-update_observations(model, new_data; verbosity=1, param1=new_value1, ...) -> updated_model
+update(model, data; verbosity=..., param1=new_value1, param2=new_value2, ...) -> updated_model
+update_observations(model, new_data; verbosity=..., param1=new_value1, ...) -> updated_model
 update_features(model, new_data; verbosity=1, param1=new_value1, ...) -> updated_model
 ```
 
@@ -101,18 +101,18 @@ See also [Density Estimation](@ref).
 
 Exactly one of the following must be implemented:
 
-| method                                      | fallback |
-|:--------------------------------------------|:---------|
-| [`fit`](@ref)`(learner, data; verbosity=1)` | none     |
-| [`fit`](@ref)`(learner; verbosity=1)`       | none     |
+| method                                                                 | fallback |
+|:-----------------------------------------------------------------------|:---------|
+| [`fit`](@ref)`(learner, data; verbosity=LearnAPI.default_verbosity())` | none     |
+| [`fit`](@ref)`(learner; verbosity=LearnAPI.default_verbosity())`       | none     |
 
 ### Updating
 
 | method                                                                               | fallback | compulsory? |
 |:-------------------------------------------------------------------------------------|:---------|-------------|
-| [`update`](@ref)`(model, data; verbosity=1, hyperparameter_updates...)`              | none     | no          |
-| [`update_observations`](@ref)`(model, data; verbosity=1, hyperparameter_updates...)` | none     | no          |
-| [`update_features`](@ref)`(model, data; verbosity=1, hyperparameter_updates...)`     | none     | no          |
+| [`update`](@ref)`(model, data; verbosity=..., hyperparameter_updates...)`              | none     | no          |
+| [`update_observations`](@ref)`(model, data; verbosity=..., hyperparameter_updates...)` | none     | no          |
+| [`update_features`](@ref)`(model, data; verbosity=..., hyperparameter_updates...)`     | none     | no          |
 
 There are some contracts governing the behaviour of the update methods, as they relate to
 a previous `fit` call. Consult the document strings for details.
@@ -124,4 +124,5 @@ fit
 update
 update_observations
 update_features
+LearnAPI.default_verbosity
 ```

src/LearnAPI.jl

@@ -1,7 +1,8 @@
 module LearnAPI
 
-include("tools.jl")
 include("types.jl")
+include("verbosity.jl")
+include("tools.jl")
 include("predict_transform.jl")
 include("fit_update.jl")
 include("target_weights_features.jl")

src/fit_update.jl

@@ -1,8 +1,8 @@
 # # FIT
 
 """
-    fit(learner, data; verbosity=1)
-    fit(learner; verbosity=1)
+    fit(learner, data; verbosity=LearnAPI.default_verbosity())
+    fit(learner; verbosity=LearnAPI.default_verbosity())
 
 Execute the machine learning or statistical algorithm with configuration `learner` using
 the provided training `data`, returning an object, `model`, on which other methods, such
@@ -17,26 +17,27 @@ model = fit(learner, (X, y))
 ŷ = predict(model, Xnew)
 ```
 
-The signature `fit(learner; verbosity=1)` (no `data`) is provided by learners that do not
-generalize to new observations (called *static algorithms*). In that case,
+The signature `fit(learner; verbosity=...)` (no `data`) is provided by learners that do
+not generalize to new observations (called *static algorithms*). In that case,
 `transform(model, data)` or `predict(model, ..., data)` carries out the actual algorithm
 execution, writing any byproducts of that operation to the mutable object `model` returned
 by `fit`.
 
 Use `verbosity=0` for warnings only, and `-1` for silent training.
 
-See also [`predict`](@ref), [`transform`](@ref), [`inverse_transform`](@ref),
-[`LearnAPI.functions`](@ref), [`obs`](@ref).
+See also [`LearnAPI.default_verbosity`](@ref), [`predict`](@ref), [`transform`](@ref),
+[`inverse_transform`](@ref), [`LearnAPI.functions`](@ref), [`obs`](@ref).
 
 # Extended help
 
 # New implementations
 
 Implementation of exactly one of the signatures is compulsory. If `fit(learner;
-verbosity=1)` is implemented, then the trait [`LearnAPI.is_static`](@ref) must be
+verbosity=...)` is implemented, then the trait [`LearnAPI.is_static`](@ref) must be
 overloaded to return `true`.
 
-The signature must include `verbosity`.
+The signature must include `verbosity` with [`LearnAPI.default_verbosity()`](@ref) as
+default.
 
 If `data` encapsulates a *target* variable, as defined in LearnAPI.jl documentation, then
 [`LearnAPI.target(data)`](@ref) must be overloaded to return it. If [`predict`](@ref) or
@@ -59,7 +60,7 @@ function fit end
 # # UPDATE AND COUSINS
 
 """
-    update(model, data; verbosity=1, hyperparam_replacements...)
+    update(model, data; verbosity=LearnAPI.default_verbosity(), hyperparam_replacements...)
 
 Return an updated version of the `model` object returned by a previous [`fit`](@ref) or
 `update` call, but with the specified hyperparameter replacements, in the form `p1=value1,
@@ -98,7 +99,12 @@ See also [`LearnAPI.clone`](@ref)
 function update end
 
 """
-    update_observations(model, new_data; verbosity=1, parameter_replacements...)
+    update_observations(
+        model,
+        new_data;
+        parameter_replacements...,
+        verbosity=LearnAPI.default_verbosity(),
+    )
 
 Return an updated version of the `model` object returned by a previous [`fit`](@ref) or
 `update` call given the new observations present in `new_data`. One may additionally
@@ -134,7 +140,12 @@ See also [`LearnAPI.clone`](@ref).
 function update_observations end
 
 """
-    update_features(model, new_data; verbosity=1, parameter_replacements...)
+    update_features(
+        model,
+        new_data;
+        parameter_replacements...,
+        verbosity=LearnAPI.default_verbosity(),
+    )
 
 Return an updated version of the `model` object returned by a previous [`fit`](@ref) or
 `update` call given the new features encapsulated in `new_data`. One may additionally

src/verbosity.jl

@@ -0,0 +1,26 @@
+const DEFAULT_VERBOSITY = Ref(1)
+
+"""
+    LearnAPI.default_verbosity()
+    LearnAPI.default_verbosity(level::Int)
+
+Respectively return, or set, the default `verbosity` level for LearnAPI.jl methods that
+support it, which includes [`fit`](@ref), [`update`](@ref),
+[`update_observations`](@ref), and [`update_features`](@ref). The effect in a top-level
+call is generally:
+
+
+
+| `level` | behaviour                         |
+|:--------|:----------------------------------|
+| 1       | informational                     |
+| 0       | warnings only                     |
+| -1      | silent                            |
+
+
+Methods consuming `verbosity` generally call other verbosity-supporting methods
+at one level lower, so increasing `verbosity` beyond `1` may be useful.
+
+"""
+default_verbosity() = DEFAULT_VERBOSITY[]
+default_verbosity(level) = (DEFAULT_VERBOSITY[] = level)

test/runtests.jl

@@ -2,6 +2,7 @@ using Test
 
 test_files = [
     "tools.jl",
+    "verbosity.jl",
     "traits.jl",
     "clone.jl",
     "predict_transform.jl",

test/verbosity.jl

@@ -0,0 +1,7 @@
+using Test
+
+@test LearnAPI.default_verbosity() ==1
+LearnAPI.default_verbosity(42)
+@test LearnAPI.default_verbosity() == 42
+
+true