retirada do escopo main do arquivo pca.py

pyFTS/common/transformations/pca.py

@@ -0,0 +1,22 @@
+from sklearn.decomposition import PCA
+from pyFTS.common.Transformations import Transformation
+import pandas as pd
+
+class PCATransformation(Transformation):
+    def __init__(self):
+        self.pca = PCA(n_components=2)
+        self.is_multivariate = True
+
+
+    def apply(self, data, param=None, **kwargs):
+        endogen_variable = kwargs.get('endogen_variable', None)
+        names = kwargs.get('names', ('x', 'y'))
+        if endogen_variable not in data.columns:
+            endogen_variable = None
+        cols = data.columns[:-1] if endogen_variable is None else [col for col in data.columns if
+                                                                   col != endogen_variable]
+        self.pca.fit(data[cols].values)
+        transformed = self.pca.transform(data[cols])
+        new = pd.DataFrame(transformed, columns=list(names))
+        new[endogen_variable] = data[endogen_variable].values
+        return new