Isolation forest results every value -1












1












$begingroup$


I am trying out isolation forest to detect outliers in a specific target column of my dataset. The dataset contains 188 rows of data with 178 rows with the same value for that target column and the isolation forest gives out every single value -1. Is that a bug or should I take it as that the values are fine? Here is a piece of the code. (I know I need to stop using ix).



import pandas as pd
import numpy as np
from sklearn.ensemble import IsolationForest

df1 = pd.read_csv('C:/Users/smotapar/Desktop/ase/source/data.csv')
clf = IsolationForest(n_estimators=200, random_state=10, bootstrap=False)
clf.fit(df1.ix[:,"target"].values.reshape(-1, 1))
clf.predict(df1.ix[:,"target"].values.reshape(-1, 1))


Which gives out an output:




array([-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1])




So, what did I do wrong? If I didn't, why is the output like this?










share|improve this question











$endgroup$












  • $begingroup$
    What's your dataset?
    $endgroup$
    – Aditya
    Mar 19 '18 at 3:29










  • $begingroup$
    Just send your dataset here. I will try.
    $endgroup$
    – Shivanya
    2 days ago
















1












$begingroup$


I am trying out isolation forest to detect outliers in a specific target column of my dataset. The dataset contains 188 rows of data with 178 rows with the same value for that target column and the isolation forest gives out every single value -1. Is that a bug or should I take it as that the values are fine? Here is a piece of the code. (I know I need to stop using ix).



import pandas as pd
import numpy as np
from sklearn.ensemble import IsolationForest

df1 = pd.read_csv('C:/Users/smotapar/Desktop/ase/source/data.csv')
clf = IsolationForest(n_estimators=200, random_state=10, bootstrap=False)
clf.fit(df1.ix[:,"target"].values.reshape(-1, 1))
clf.predict(df1.ix[:,"target"].values.reshape(-1, 1))


Which gives out an output:




array([-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1])




So, what did I do wrong? If I didn't, why is the output like this?










share|improve this question











$endgroup$












  • $begingroup$
    What's your dataset?
    $endgroup$
    – Aditya
    Mar 19 '18 at 3:29










  • $begingroup$
    Just send your dataset here. I will try.
    $endgroup$
    – Shivanya
    2 days ago














1












1








1


0



$begingroup$


I am trying out isolation forest to detect outliers in a specific target column of my dataset. The dataset contains 188 rows of data with 178 rows with the same value for that target column and the isolation forest gives out every single value -1. Is that a bug or should I take it as that the values are fine? Here is a piece of the code. (I know I need to stop using ix).



import pandas as pd
import numpy as np
from sklearn.ensemble import IsolationForest

df1 = pd.read_csv('C:/Users/smotapar/Desktop/ase/source/data.csv')
clf = IsolationForest(n_estimators=200, random_state=10, bootstrap=False)
clf.fit(df1.ix[:,"target"].values.reshape(-1, 1))
clf.predict(df1.ix[:,"target"].values.reshape(-1, 1))


Which gives out an output:




array([-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1])




So, what did I do wrong? If I didn't, why is the output like this?










share|improve this question











$endgroup$




I am trying out isolation forest to detect outliers in a specific target column of my dataset. The dataset contains 188 rows of data with 178 rows with the same value for that target column and the isolation forest gives out every single value -1. Is that a bug or should I take it as that the values are fine? Here is a piece of the code. (I know I need to stop using ix).



import pandas as pd
import numpy as np
from sklearn.ensemble import IsolationForest

df1 = pd.read_csv('C:/Users/smotapar/Desktop/ase/source/data.csv')
clf = IsolationForest(n_estimators=200, random_state=10, bootstrap=False)
clf.fit(df1.ix[:,"target"].values.reshape(-1, 1))
clf.predict(df1.ix[:,"target"].values.reshape(-1, 1))


Which gives out an output:




array([-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1])




So, what did I do wrong? If I didn't, why is the output like this?







python scikit-learn pandas outlier






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Mar 19 '18 at 7:53









tuomastik

745418




745418










asked Mar 19 '18 at 2:53









RamRam

313




313












  • $begingroup$
    What's your dataset?
    $endgroup$
    – Aditya
    Mar 19 '18 at 3:29










  • $begingroup$
    Just send your dataset here. I will try.
    $endgroup$
    – Shivanya
    2 days ago


















  • $begingroup$
    What's your dataset?
    $endgroup$
    – Aditya
    Mar 19 '18 at 3:29










  • $begingroup$
    Just send your dataset here. I will try.
    $endgroup$
    – Shivanya
    2 days ago
















$begingroup$
What's your dataset?
$endgroup$
– Aditya
Mar 19 '18 at 3:29




$begingroup$
What's your dataset?
$endgroup$
– Aditya
Mar 19 '18 at 3:29












$begingroup$
Just send your dataset here. I will try.
$endgroup$
– Shivanya
2 days ago




$begingroup$
Just send your dataset here. I will try.
$endgroup$
– Shivanya
2 days ago










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