Loading...

vastorbit.machine_learning.vast.ensemble.IsolationForest

class vastorbit.machine_learning.vast.ensemble.IsolationForest(name: str = None, overwrite_model: bool = False, **kwargs)

Creates an IsolationForest object using scikit-learn for training and the scalability of VAST DataBase for the inferences.

Parameters:
  • name (str, optional) – Name of the model. The model is stored in the database.

  • overwrite_model (bool, optional) – If set to True, training a model with the same name as an existing model overwrites the existing model.

  • **kwargs (scikit-learn model parameters.)

Variables:
  • created (Many attributes are)

  • phase. (during the fitting)

  • trees_ (list of BinaryTreeAnomaly) – Tree models are instances of ` BinaryTreeAnomaly, each possessing various attributes. For more detailed information, refer to the documentation for BinaryTreeAnomaly.

  • psy_ (int) – Sampling size used to compute the final score.

  • n_estimators_ (int) – The number of model estimators.

  • note:: (..) – All attributes can be accessed using the get_attributes() method.

Examples

The following examples provide a basic understanding of usage. For more detailed examples, please refer to the Machine Learning or the Examples section on the website.

Load data for machine learning

We import vastorbit:

import vastorbit as vo

Hint

By assigning an alias to vastorbit, we mitigate the risk of code collisions with other libraries. This precaution is necessary because vastorbit uses commonly known function names like “average” and “median”, which can potentially lead to naming conflicts. The use of an alias ensures that the functions from vastorbit are used as intended without interfering with functions from other libraries.

For this example, we will use the winequality dataset.

import vastorbit.datasets as vod

data = vod.load_winequality()
123
fixed_acidity
Decimal(6, 3)
123
volatile_acidity
Decimal(7, 4)
123
citric_acid
Decimal(6, 3)
123
residual_sugar
Decimal(7, 3)
123
chlorides
Double
123
free_sulfur_dioxide
Decimal(7, 2)
123
total_sulfur_dioxide
Decimal(7, 2)
123
density
Double
123
ph
Decimal(6, 3)
123
sulphates
Decimal(6, 3)
123
alcohol
Double
123
quality
Integer
123
good
Integer
Abc
color
Varchar(20)
16.30.670.4812.60.05257.0222.00.99793.170.529.360white
27.40.40.295.40.04431.0122.00.9943.30.511.181white
37.10.260.312.20.04429.0128.00.99373.340.6410.981white
49.00.310.486.60.04311.073.00.99382.90.3811.650white
56.30.390.246.90.0699.0117.00.99423.150.3510.240white
68.20.220.366.80.03412.090.00.99443.010.3810.581white
77.10.190.283.60.03316.078.00.9932.910.7811.460white
87.30.250.3613.10.0535.0200.00.99863.040.468.971white
97.90.20.341.20.0429.0118.00.99323.140.4110.660white
107.10.260.325.90.03739.097.00.99343.310.411.660white
117.00.20.345.70.03532.083.00.99283.190.4611.560white
126.90.30.334.10.03526.0155.00.99253.250.7912.381white
138.10.290.497.10.04222.0124.00.99443.140.4110.860white
145.80.170.31.40.03755.0130.00.99093.290.3811.360white
155.90.4150.020.80.03822.063.00.99323.360.369.350white
166.60.230.261.30.04516.0128.00.99343.360.610.060white
178.60.550.3515.550.05735.5366.51.00013.040.6311.030white
186.90.350.741.00.04418.0132.00.9923.130.5510.250white
197.60.140.741.60.0427.0103.00.99163.070.410.871white
209.20.280.4911.80.04229.0137.00.9983.10.3410.140white
216.20.180.494.50.04717.090.00.99193.270.3711.660white
225.30.1650.241.10.05125.0105.00.99253.320.479.150white
239.80.250.7410.00.05636.0225.00.99773.060.4310.040white
248.10.290.497.10.04222.0124.00.99443.140.4110.860white
256.80.220.490.90.05226.0128.00.9913.250.3511.460white
267.20.220.491.00.04534.0140.00.993.050.3412.760white
277.40.250.491.10.04235.0156.00.99173.130.5511.350white
288.20.180.491.10.03328.081.00.99233.00.6810.471white
296.10.220.491.50.05118.087.00.99283.30.469.650white
307.00.390.241.00.0488.0119.00.99233.00.3110.140white
316.10.220.491.50.05118.087.00.99283.30.469.650white
326.50.360.492.90.0316.094.00.99023.10.4912.171white
337.10.290.491.20.03132.099.00.98933.070.3312.260white
347.40.250.491.10.04235.0156.00.99173.130.5511.350white
356.90.230.2414.20.05319.094.00.99823.170.59.650white
368.50.560.7417.850.05151.0243.01.00052.990.79.250white
378.20.180.491.10.03328.081.00.99233.00.6810.471white
386.30.230.497.10.0567.0210.00.99513.230.349.550white
396.10.250.497.60.05267.0226.00.99563.160.478.950white
407.20.260.7413.60.0556.0162.00.9983.030.448.850white
417.20.310.241.40.05717.0117.00.99283.160.3510.550white
428.00.250.491.20.06127.0117.00.99383.080.349.450white
437.00.180.495.30.0434.0125.00.99143.240.412.260white
447.80.430.4913.00.03337.0158.00.99553.140.3511.360white
458.30.20.744.450.04433.0130.00.99243.250.4212.260white
466.30.270.491.20.06335.092.00.99113.380.4212.260white
477.40.160.491.20.05518.0150.00.99173.230.4711.260white
487.40.160.491.20.05518.0150.00.99173.230.4711.260white
496.90.190.496.60.03649.0172.00.99323.20.2711.560white
507.80.430.4913.00.03337.0158.00.99553.140.3511.360white
517.20.40.491.10.04811.0138.00.99293.010.429.350white
527.80.430.4913.00.03337.0158.00.99553.140.3511.360white
537.60.520.4914.00.03437.0156.00.99583.140.3811.871white
548.30.210.4919.80.05450.0231.01.00122.990.549.250white
556.90.340.7411.20.06944.0150.00.99683.00.819.250white
566.30.270.491.20.06335.092.00.99113.380.4212.260white
578.30.20.744.450.04433.0130.00.99243.250.4212.260white
587.10.220.742.70.04442.0144.00.9913.310.4112.260white
597.90.110.494.50.04827.0133.00.99463.240.4210.660white
608.50.170.743.60.0529.0128.00.99283.280.412.460white
616.40.1450.495.40.04854.0164.00.99463.560.4410.860white
627.40.160.491.20.05518.0150.00.99173.230.4711.260white
638.30.190.491.20.05111.0137.00.99183.060.4611.060white
648.00.440.499.10.03146.0151.00.99263.160.2712.781white
657.00.20.740.80.04419.0163.00.99313.460.5310.250white
666.90.190.496.60.03649.0172.00.99323.20.2711.560white
677.10.250.493.00.0330.096.00.99033.130.3912.371white
686.50.240.241.60.04615.060.00.99283.190.399.850white
697.20.40.491.10.04811.0138.00.99293.010.429.350white
707.60.520.4914.00.03437.0156.00.99583.140.3811.871white
717.80.430.4913.00.03337.0158.00.99553.140.3511.360white
727.80.210.491.350.0526.048.00.99113.150.2811.450white
737.00.20.495.90.03839.0128.00.99383.210.4810.860white
746.90.250.243.60.05713.085.00.99422.990.489.540white
757.20.080.491.30.0518.0148.00.99453.460.4410.260white
767.10.850.498.70.02840.0184.00.99623.220.3610.750white
777.60.510.241.20.0410.0104.00.9923.050.2910.860white
787.90.220.244.60.04439.0159.00.99272.990.2811.560white
797.70.160.492.00.05620.0124.00.99483.320.4910.760white
807.20.080.491.30.0518.0148.00.99453.460.4410.260white
816.60.250.241.70.04826.0124.00.99423.370.610.160white
826.70.160.492.40.04657.0187.00.99523.620.8110.460white
836.90.250.243.60.05713.085.00.99422.990.489.540white
847.50.320.244.60.0538.0134.00.99583.140.59.130white
857.40.280.491.50.03420.0126.00.99182.980.3910.660white
866.20.150.490.90.03317.051.00.99323.30.79.460white
876.70.250.7419.40.05444.0169.01.00043.510.459.860white
886.50.260.7413.30.04468.0224.00.99723.180.549.560white
897.90.160.7417.850.03752.0187.00.99982.990.419.350white
905.60.1850.491.10.0328.0117.00.99183.550.4510.360white
917.50.20.491.30.0318.097.00.99183.060.6211.150white
928.00.30.499.40.04647.0188.00.99643.140.4810.050white
938.00.340.499.00.03339.0180.00.99363.130.3812.381white
947.70.350.498.650.03342.0186.00.99313.140.3812.481white
957.60.290.499.60.0345.0197.00.99383.130.3812.371white
966.70.620.241.10.0396.062.00.99343.410.3210.450white
976.80.270.491.20.04435.0126.00.993.130.4812.171white
987.70.270.491.80.04123.086.00.99143.160.4212.560white
996.70.510.242.10.04314.0155.00.99043.220.613.060white
1007.40.190.499.30.0326.0132.00.9942.990.3211.071white
Rows: 1-100 | Columns: 14

Note

vastorbit offers a wide range of sample datasets that are ideal for training and testing purposes. You can explore the full list of available datasets in the Datasets, which provides detailed information on each dataset and how to use them effectively. These datasets are invaluable resources for honing your data analysis and machine learning skills within the vastorbit environment.

Model Initialization

First we import the IsolationForest model:

from vastorbit.machine_learning.vast import IsolationForest

Then we can create the model:

model = IsolationForest(
    n_estimators = 5,
)

Important

The model name is crucial for the model management system and versioning. It’s highly recommended to provide a name if you plan to reuse the model later.

Model Training

We can now fit the model:

model.fit(data, X = ["density", "sulphates"])

Important

To train a model, you can directly use the VastFrame or the name of the relation stored in the database. The test set is optional and is only used to compute the test metrics. In vastorbit, we don’t work using X matrices and y vectors. Instead, we work directly with lists of predictors and the response name.

Hint

For clustering and anomaly detection, the use of predictors is optional. In such cases, all available predictors are considered, which can include solely numerical variables or a combination of numerical and categorical variables, depending on the model’s capabilities.

Prediction

Prediction is straight-forward:

model.predict(data, ["density", "sulphates"])
123
fixed_acidity
Decimal(6, 3)
123
volatile_acidity
Decimal(7, 4)
123
citric_acid
Decimal(6, 3)
123
residual_sugar
Decimal(7, 3)
123
chlorides
Double
123
free_sulfur_dioxide
Decimal(7, 2)
123
total_sulfur_dioxide
Decimal(7, 2)
123
density
Double
123
ph
Decimal(6, 3)
123
sulphates
Decimal(6, 3)
123
alcohol
Double
123
quality
Integer
123
good
Integer
Abc
color
Varchar(20)
123
isolationforest_default_vastorbit_tmp_isolationforest_memory_admin_f8679d10754811f1becdea8c65480234_
Integer
16.30.670.4812.60.05257.0222.00.99793.170.529.360white0
27.40.40.295.40.04431.0122.00.9943.30.511.181white0
37.10.260.312.20.04429.0128.00.99373.340.6410.981white0
49.00.310.486.60.04311.073.00.99382.90.3811.650white0
56.30.390.246.90.0699.0117.00.99423.150.3510.240white0
68.20.220.366.80.03412.090.00.99443.010.3810.581white0
77.10.190.283.60.03316.078.00.9932.910.7811.460white0
87.30.250.3613.10.0535.0200.00.99863.040.468.971white0
97.90.20.341.20.0429.0118.00.99323.140.4110.660white0
107.10.260.325.90.03739.097.00.99343.310.411.660white0
117.00.20.345.70.03532.083.00.99283.190.4611.560white0
126.90.30.334.10.03526.0155.00.99253.250.7912.381white0
138.10.290.497.10.04222.0124.00.99443.140.4110.860white0
145.80.170.31.40.03755.0130.00.99093.290.3811.360white0
155.90.4150.020.80.03822.063.00.99323.360.369.350white0
166.60.230.261.30.04516.0128.00.99343.360.610.060white0
178.60.550.3515.550.05735.5366.51.00013.040.6311.030white0
186.90.350.741.00.04418.0132.00.9923.130.5510.250white0
197.60.140.741.60.0427.0103.00.99163.070.410.871white0
209.20.280.4911.80.04229.0137.00.9983.10.3410.140white0
216.20.180.494.50.04717.090.00.99193.270.3711.660white0
225.30.1650.241.10.05125.0105.00.99253.320.479.150white0
239.80.250.7410.00.05636.0225.00.99773.060.4310.040white0
248.10.290.497.10.04222.0124.00.99443.140.4110.860white0
256.80.220.490.90.05226.0128.00.9913.250.3511.460white0
267.20.220.491.00.04534.0140.00.993.050.3412.760white0
277.40.250.491.10.04235.0156.00.99173.130.5511.350white0
288.20.180.491.10.03328.081.00.99233.00.6810.471white0
296.10.220.491.50.05118.087.00.99283.30.469.650white0
307.00.390.241.00.0488.0119.00.99233.00.3110.140white0
316.10.220.491.50.05118.087.00.99283.30.469.650white0
326.50.360.492.90.0316.094.00.99023.10.4912.171white0
337.10.290.491.20.03132.099.00.98933.070.3312.260white0
347.40.250.491.10.04235.0156.00.99173.130.5511.350white0
356.90.230.2414.20.05319.094.00.99823.170.59.650white0
368.50.560.7417.850.05151.0243.01.00052.990.79.250white0
378.20.180.491.10.03328.081.00.99233.00.6810.471white0
386.30.230.497.10.0567.0210.00.99513.230.349.550white0
396.10.250.497.60.05267.0226.00.99563.160.478.950white0
407.20.260.7413.60.0556.0162.00.9983.030.448.850white0
417.20.310.241.40.05717.0117.00.99283.160.3510.550white0
428.00.250.491.20.06127.0117.00.99383.080.349.450white0
437.00.180.495.30.0434.0125.00.99143.240.412.260white0
447.80.430.4913.00.03337.0158.00.99553.140.3511.360white0
458.30.20.744.450.04433.0130.00.99243.250.4212.260white0
466.30.270.491.20.06335.092.00.99113.380.4212.260white0
477.40.160.491.20.05518.0150.00.99173.230.4711.260white0
487.40.160.491.20.05518.0150.00.99173.230.4711.260white0
496.90.190.496.60.03649.0172.00.99323.20.2711.560white0
507.80.430.4913.00.03337.0158.00.99553.140.3511.360white0
517.20.40.491.10.04811.0138.00.99293.010.429.350white0
527.80.430.4913.00.03337.0158.00.99553.140.3511.360white0
537.60.520.4914.00.03437.0156.00.99583.140.3811.871white0
548.30.210.4919.80.05450.0231.01.00122.990.549.250white0
556.90.340.7411.20.06944.0150.00.99683.00.819.250white0
566.30.270.491.20.06335.092.00.99113.380.4212.260white0
578.30.20.744.450.04433.0130.00.99243.250.4212.260white0
587.10.220.742.70.04442.0144.00.9913.310.4112.260white0
597.90.110.494.50.04827.0133.00.99463.240.4210.660white0
608.50.170.743.60.0529.0128.00.99283.280.412.460white0
616.40.1450.495.40.04854.0164.00.99463.560.4410.860white0
627.40.160.491.20.05518.0150.00.99173.230.4711.260white0
638.30.190.491.20.05111.0137.00.99183.060.4611.060white0
648.00.440.499.10.03146.0151.00.99263.160.2712.781white0
657.00.20.740.80.04419.0163.00.99313.460.5310.250white0
666.90.190.496.60.03649.0172.00.99323.20.2711.560white0
677.10.250.493.00.0330.096.00.99033.130.3912.371white0
686.50.240.241.60.04615.060.00.99283.190.399.850white0
697.20.40.491.10.04811.0138.00.99293.010.429.350white0
707.60.520.4914.00.03437.0156.00.99583.140.3811.871white0
717.80.430.4913.00.03337.0158.00.99553.140.3511.360white0
727.80.210.491.350.0526.048.00.99113.150.2811.450white0
737.00.20.495.90.03839.0128.00.99383.210.4810.860white0
746.90.250.243.60.05713.085.00.99422.990.489.540white0
757.20.080.491.30.0518.0148.00.99453.460.4410.260white0
767.10.850.498.70.02840.0184.00.99623.220.3610.750white0
777.60.510.241.20.0410.0104.00.9923.050.2910.860white0
787.90.220.244.60.04439.0159.00.99272.990.2811.560white0
797.70.160.492.00.05620.0124.00.99483.320.4910.760white0
807.20.080.491.30.0518.0148.00.99453.460.4410.260white0
816.60.250.241.70.04826.0124.00.99423.370.610.160white0
826.70.160.492.40.04657.0187.00.99523.620.8110.460white0
836.90.250.243.60.05713.085.00.99422.990.489.540white0
847.50.320.244.60.0538.0134.00.99583.140.59.130white0
857.40.280.491.50.03420.0126.00.99182.980.3910.660white0
866.20.150.490.90.03317.051.00.99323.30.79.460white0
876.70.250.7419.40.05444.0169.01.00043.510.459.860white0
886.50.260.7413.30.04468.0224.00.99723.180.549.560white0
897.90.160.7417.850.03752.0187.00.99982.990.419.350white0
905.60.1850.491.10.0328.0117.00.99183.550.4510.360white0
917.50.20.491.30.0318.097.00.99183.060.6211.150white0
928.00.30.499.40.04647.0188.00.99643.140.4810.050white0
938.00.340.499.00.03339.0180.00.99363.130.3812.381white0
947.70.350.498.650.03342.0186.00.99313.140.3812.481white0
957.60.290.499.60.0345.0197.00.99383.130.3812.371white0
966.70.620.241.10.0396.062.00.99343.410.3210.450white0
976.80.270.491.20.04435.0126.00.993.130.4812.171white0
987.70.270.491.80.04123.086.00.99143.160.4212.560white0
996.70.510.242.10.04314.0155.00.99043.220.613.060white0
1007.40.190.499.30.0326.0132.00.9942.990.3211.071white0
Rows: 1-100 | Columns: 15

Plots - Anomaly Detection

Plots highlighting the outliers can be easily drawn using:

model.plot()

Note

Most anomaly detection methods produce a score. In scenarios involving 2 or 3 predictors, using a bubble plot to visualize the model’s results is a straightforward approach. In such plots, the size of each bubble corresponds to the anomaly score.

Plots - Tree

Tree models can be visualized by drawing their tree plots. For more examples, check out Machine Learning - Tree Plots.

model.plot_tree()
../_images/machine_learning_VAST_tree_isolation_for_.png

Note

The above example may not render properly in the doc because of the huge size of the tree. But it should render nicely in jupyter environment.

In order to plot graph using graphviz separately, you can extract the graphviz DOT file code as follows:

model.to_graphviz()

This string can then be copied into a DOT file which can be parsed by graphviz.

Plots - Contour

In order to understand the parameter space, we can also look at the contour plots:

model.contour()

Note

Machine learning models with two predictors can usually benefit from their own contour plot. This visual representation aids in exploring predictions and gaining a deeper understanding of how these models perform in different scenarios. Please refer to Contour Plot for more examples.

Parameter Modification

In order to see the parameters:

model.get_params()

And to manually change some of the parameters:

model.set_params({'max_depth': 5})

Model Exporting

To Memmodel

model.to_memmodel()

Note

MemModel objects serve as in-memory representations of machine learning models. They can be used for both in-database and in-memory prediction tasks. These objects can be pickled in the same way that you would pickle a scikit-learn model.

The preceding methods for exporting the model use MemModel, and it is recommended to use MemModel directly.

To SQL

You can get the SQL query equivalent of the IsolationForest model by:

model.to_sql()

Note

This SQL query can be directly used in any database.

Deploy SQL

To get the SQL query which uses VAST functions use below:

model.deploySQL()

To Python

To obtain the prediction function in Python syntax, use the following code:

X = [[0.9, 0.5]]
model.to_python()(X)

Hint

The to_python() method is used to retrieve the anomaly score. For specific details on how to use this method for different model types, refer to the relevant documentation for each model.

__init__(name: str = None, overwrite_model: bool = False, **kwargs) None

Methods

__init__([name, overwrite_model])

contour([nbins, chart])

Draws the model's contour plot.

decision_function(vdf[, X, name, inplace])

Returns the anomaly score using the input relation.

deploySQL([X, cutoff, contamination, ...])

Returns the SQL code needed to deploy the model.

drop()

Drops the model from the VAST DataBase.

export_models(name, path[, kind])

Exports machine learning models.

features_importance([tree_id, show, chart])

Computes the model's features importance.

fit(input_relation[, X, return_report])

Trains the model.

get_attributes([attr_name])

Returns the model attributes.

get_match_index(x, col_list[, str_check])

Returns the matching index.

get_params()

Returns the parameters of the model.

get_plotting_lib([class_name, chart, ...])

Returns the first available library (Plotly, Matplotlib) to draw a specific graphic.

get_tree([tree_id])

Returns a table with all the input tree information.

import_models(path[, schema, kind])

Imports machine learning models.

plot([max_nb_points, chart])

Draws the model.

plot_tree([tree_id, pic_path])

Draws the input tree.

predict(vdf[, X, name, cutoff, ...])

Predicts using the input relation.

set_params([parameters])

Sets the parameters of the model.

summarize()

Summarizes the model.

to_binary(path)

Exports the model to the VAST Binary format.

to_graphviz([tree_id, classes_color, ...])

Returns the code for a Graphviz tree.

to_memmodel()

Converts the model to an InMemory object that can be used for different types of predictions.

to_python([return_proba, ...])

Returns the Python function needed for in-memory scoring without using built-in VAST functions.

to_sql([X, return_proba, ...])

Returns the SQL code needed to deploy the model without using built-in VAST functions.

Attributes