added :taregt-datatypes

fixes #26

CHANGELOG.md

@@ -1,3 +1,7 @@
+
+unreleased
+* added :target-datatypes in train result and clarified expected 'shape' of prediction
+
 0.10.3
  * re-added data.json dependency
 

src/scicloj/metamorph/ml.clj

@@ -588,7 +588,17 @@
   * `:options` - the options passed in.
   * `:id` - new randomly generated UUID.
   * `:feature-columns` - vector of column names.
-  * `:target-columns` - vector of column names."
+  * `:target-columns` - vector of column names.
+  * `:target-datatypes` - map of target columns names -> target columns type 
+  * `:target-categorical-maps` - the categorical maps of the target columns, if present 
+   
+ A well behaving model implementaion should use 
+   :target-column  
+   :target-datatypes 
+   :target-categorical-maps  
+   
+   to construct its prediction dataset so that its matches with the train data target column.
+   "
   {:malli/schema [:=> [:cat [:fn dataset?] map?]
                   [map?]]}
   [dataset options]
@@ -605,14 +615,23 @@
 
         model-data (train-fn feature-ds target-ds options)
         ;; _ (errors/when-not-error (:model-as-bytes model-data)  "train-fn need to return a map with key :model-as-bytes")
+
+        targets-datatypes
+        (zipmap
+         (keys target-ds)
+         (->>
+          (vals target-ds)
+          (map meta)
+          (map :datatype)))
         cat-maps (ds-mod/dataset->categorical-xforms target-ds)]
 
     (merge
      {:model-data model-data
       :options options
       :id (UUID/randomUUID)
       :feature-columns (vec (ds/column-names feature-ds))
-      :target-columns (vec (ds/column-names target-ds))}
+      :target-columns (vec (ds/column-names target-ds))
+      :target-datatypes targets-datatypes}
      (when-not (== 0 (count cat-maps))
        {:target-categorical-maps cat-maps}))))
 
@@ -671,7 +690,15 @@
   * For regression, a single column dataset is returned with the column named after the
     target
   * For classification, a dataset is returned with a float64 column for each target
-    value and values that describe the probability distribution."
+    value and values that describe the probability distribution.
+   
+  Each implementing model should construct its prediction in a shape expressed by
+   :target-column  
+   :target-datatypes 
+   :target-categorical-maps  
+
+   it is receiving.
+   "
   {:malli/schema [:=> [:cat [:fn dataset?]
                        [:map [:options map?]
                         [:feature-columns sequential?]

test/scicloj/metamorph/classification_test.clj

@@ -47,24 +47,19 @@
         model (ml/train ds  {:model-type :metamorph.ml/dummy-classifier
                              :dummy-strategy :fixed-class
                              :fixed-class 0})
-
-
-
         prediction (ml/predict ds model)]
 
-
+    (is (= {:species :int16} (:target-datatypes model)))
     (is (= (:species prediction) (repeat 150 0)))))
 
-
-
 (deftest dummy-classification-majority []
   (let [ds (toydata/breast-cancer-ds)
         model (ml/train ds {:model-type :metamorph.ml/dummy-classifier
                             :dummy-strategy :majority-class})
 
 
         prediction (ml/predict ds model)]
-    
+
     (is (= (:class prediction) (repeat 569 0)))))