|
| 1 | + |
| 2 | +# From: |
| 3 | +# https://github.com/WinVector/pyvtreat/blob/master/Examples/UserCoders/UserCoders.ipynb |
| 4 | + |
| 5 | + |
| 6 | +import pandas |
| 7 | +import numpy |
| 8 | +import numpy.random |
| 9 | +# import seaborn |
| 10 | + |
| 11 | +import vtreat |
| 12 | +import vtreat.util |
| 13 | +import vtreat.transform |
| 14 | + |
| 15 | +have_sklearn = True |
| 16 | +try: |
| 17 | + import sklearn.linear_model |
| 18 | + import sklearn |
| 19 | +except Exception: |
| 20 | + have_sklean = False |
| 21 | + |
| 22 | + |
| 23 | +def test_user_coders(): |
| 24 | + sklearn.warnings.filterwarnings('ignore') |
| 25 | + |
| 26 | + # avoid depending on sklearn.metrics.r2_score |
| 27 | + def r_squared(*, y_true, y_pred): |
| 28 | + y_true = numpy.asarray(y_true) |
| 29 | + y_pred = numpy.asarray(y_pred) |
| 30 | + return 1 - numpy.sum((y_true - y_pred)**2)/numpy.sum((y_true - numpy.mean(y_true))**2) |
| 31 | + |
| 32 | + # %% |
| 33 | + |
| 34 | + class PolyTransform(vtreat.transform.UserTransform): |
| 35 | + """a polynomial model""" |
| 36 | + |
| 37 | + def __init__(self, *, deg=5, alpha=0.1): |
| 38 | + vtreat.transform.UserTransform.__init__(self, treatment='poly') |
| 39 | + self.models_ = None |
| 40 | + self.deg = deg |
| 41 | + self.alpha = alpha |
| 42 | + |
| 43 | + def poly_terms(self, vname, vec): |
| 44 | + vec = numpy.asarray(vec) |
| 45 | + r = pandas.DataFrame({'x': vec}) |
| 46 | + for d in range(1, self.deg + 1): |
| 47 | + r[vname + '_' + str(d)] = vec ** d |
| 48 | + return r |
| 49 | + |
| 50 | + def fit(self, X, y): |
| 51 | + self.models_ = {} |
| 52 | + self.incoming_vars_ = [] |
| 53 | + self.derived_vars_ = [] |
| 54 | + for v in X.columns: |
| 55 | + if vtreat.util.can_convert_v_to_numeric(X[v]): |
| 56 | + X_v = self.poly_terms(v, X[v]) |
| 57 | + model_v = sklearn.linear_model.Ridge(alpha=self.alpha).fit(X_v, y) |
| 58 | + new_var = v + "_poly" |
| 59 | + self.models_[v] = (model_v, [c for c in X_v.columns], new_var) |
| 60 | + self.incoming_vars_.append(v) |
| 61 | + self.derived_vars_.append(new_var) |
| 62 | + return self |
| 63 | + |
| 64 | + def transform(self, X): |
| 65 | + r = pandas.DataFrame() |
| 66 | + for k, v in self.models_.items(): |
| 67 | + model_k = v[0] |
| 68 | + cols_k = v[1] |
| 69 | + new_var = v[2] |
| 70 | + X_k = self.poly_terms(k, X[k]) |
| 71 | + xform_k = model_k.predict(X_k) |
| 72 | + r[new_var] = xform_k |
| 73 | + return r |
| 74 | + |
| 75 | + # %% |
| 76 | + |
| 77 | + d = pandas.DataFrame({'x': [i for i in range(100)]}) |
| 78 | + d['y'] = numpy.sin(0.2 * d['x']) + 0.2 * numpy.random.normal(size=d.shape[0]) |
| 79 | + d.head() |
| 80 | + |
| 81 | + # %% |
| 82 | + |
| 83 | + step = PolyTransform(deg=10) |
| 84 | + |
| 85 | + # %% |
| 86 | + |
| 87 | + fit = step.fit_transform(d[['x']], d['y']) |
| 88 | + fit['x'] = d['x'] |
| 89 | + fit.head() |
| 90 | + |
| 91 | + # %% |
| 92 | + |
| 93 | + # seaborn.scatterplot(x='x', y='y', data=d) |
| 94 | + # seaborn.lineplot(x='x', y='x_poly', data=fit, color='red', alpha=0.5) |
| 95 | + |
| 96 | + # %% |
| 97 | + |
| 98 | + transform = vtreat.NumericOutcomeTreatment( |
| 99 | + outcome_name='y', |
| 100 | + params=vtreat.vtreat_parameters({ |
| 101 | + 'filter_to_recommended': False, |
| 102 | + 'user_transforms': [PolyTransform(deg=10)] |
| 103 | + })) |
| 104 | + |
| 105 | + # %% |
| 106 | + |
| 107 | + transform.fit(d, d['y']) |
| 108 | + |
| 109 | + # %% |
| 110 | + |
| 111 | + transform.score_frame_ |
| 112 | + |
| 113 | + # %% |
| 114 | + |
| 115 | + x2_overfit = transform.transform(d) |
| 116 | + |
| 117 | + # %% |
| 118 | + # seaborn.scatterplot(x='x', y='y', data=x2_overfit) |
| 119 | + # seaborn.lineplot(x='x', y='x_poly', data=x2_overfit, color='red', alpha=0.5) |
| 120 | + |
| 121 | + # %% |
| 122 | + |
| 123 | + x2 = transform.fit_transform(d, d['y']) |
| 124 | + |
| 125 | + # %% |
| 126 | + |
| 127 | + transform.score_frame_ |
| 128 | + |
| 129 | + # %% |
| 130 | + |
| 131 | + x2.head() |
| 132 | + |
| 133 | + # %% |
| 134 | + |
| 135 | + # seaborn.scatterplot(x='x', y='y', data=x2) |
| 136 | + # seaborn.lineplot(x='x', y='x_poly', data=x2, color='red', alpha=0.5) |
| 137 | + |
| 138 | + # %% |
| 139 | + |
| 140 | + |
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