Polynomial Regression using Python

[nabitti]

I'm following this tutorial in youtube (https://www.youtube.com/watch?v=CPuDfovUuTs) to create a polynomial regresssion in Power BI. I have the same exact script but I'm getting this error:

Error Message:

Þγτћŏл §сґĩρţ ęѓгŏř.

Traceback (most recent call last):

  File "PythonScriptWrapper.PY", line 41, in <module>

    y_pred_p = model.predict(poly_feat.fit_transform(param_val))

  File "C:\Users\Nabila\miniconda3\envs\std_env\lib\site-packages\sklearn\base.py", line 690, in fit_transform

    return self.fit(X, **fit_params).transform(X)

  File "C:\Users\Nabila\miniconda3\envs\std_env\lib\site-packages\sklearn\preprocessing\_data.py", line 1513, in fit

    X, accept_sparse=True).shape

  File "C:\Users\Nabila\miniconda3\envs\std_env\lib\site-packages\sklearn\base.py", line 420, in _validate_data

    X = check_array(X, **check_params)

  File "C:\Users\Nabila\miniconda3\envs\std_env\lib\site-packages\sklearn\utils\validation.py", line 73, in inner_f

    return f(**kwargs)

  File "C:\Users\Nabila\miniconda3\envs\std_env\lib\site-packages\sklearn\utils\validation.py", line 617, in check_array

    "if it contains a single sample.".format(array))

ValueError: Expected 2D array, got scalar array instead:

array=5.

Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.

Note: I'm using Python with Miniconda so the file path I have specified in Power BI is C\Nabila\miniconda3\envs\std_env

and I have all the packages numpy, sklearn, pandas and matplotlib installed. It's worthy to emntion that I created the environment using Python 3.6 following this tutorial (https://medium.com/@pbabbott/how-to-connect-power-bi-and-python-on-windows-10-b131a36f4b44)

I tried many things but cant get it working , please help

[v-deddai1-msft]

Hi @nabitti ,

Please refer to the following links that have similar issues to yours：

https://stackoverflow.com/questions/54296377/valueerror-expected-2d-array-got-scalar-array-instead

https://datascience.stackexchange.com/questions/53048/expected-2d-array-got-scalar-array-instead

https://datascience.stackexchange.com/questions/52902/valueerror-expected-2d-array-got-scalar-array-...

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Best Regards,

Dedmon Dai

[nabitti]

Hello  @v-deddai1-msft , thank you for your reply.

I followed the links you mentioned and modified my script but now I have this other error that I do not know how to correct.
This is my script:

# dataset = pandas.DataFrame(Hour of Workday, Avg Quality, Valor Parámetro 2)

# dataset = dataset.drop_duplicates()

import matplotlib.pyplot as plt

import numpy as np

from sklearn.linear_model import LinearRegression

from sklearn.preprocessing import PolynomialFeatures

#split the dataset

X = dataset.iloc[:,0:1].values

X =X.reshape(-1,1)

y = dataset.iloc[:,1].values

y = y.reshape (-1,1)

z = dataset.iloc[2,2]

#fit the polynomial regressor to the dataset

poly_feat = PolynomialFeatures(degree=4)

X_poly = poly_feat.fit_transform(X)

model = LinearRegression()

model.fit(X_poly,y)

#chosen parameter

param_val = z

#predict quality based on the chosen hour

y_pred_p = model.predict(poly_feat.fit_transform([[param_val]]))

#Plot a range of predictions and actuals

X_line = np.arange(min(X), max(X), 0.01)

X_line=X_line.reshape((len(X_line), 1))

plt.scatter(X, y, color = 'red')

plt.plot(X_line,model.predict(poly_feat.fit_transofrm(X_line)),color='green')

plt.scatter(param_val, y_pred_p, color='green',marker='D')

plt.title('Quality Over Time', fontsize=24)

plt.xlabel('Hour of shift', fontsize=20)

plt.ylabel('Quality', fontsize=20)

#format and annotate graph

ax=plt.gca()

ax.grid(which='major', axis='both', linestyle='--')

ax.annotate('Polynomial Reg: {}'.format(np.round(y_pred_p, 2)),xy=(param_val, y_pred_p), xytext=(-90,-50), textcoords='offset points', size=15)

plt.yticks(fontsize=16)

plt.xticks(fontsize=16)

plt.show()

I have two colums that I dragged in 'values' to use for the scrpit and created a z parameter. Now the error I'm getting is this:

Error Message:
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Traceback (most recent call last):
File "PythonScriptWrapper.PY", line 50, in <module>
plt.plot(X_line,model.predict(poly_feat.fit_transofrm(X_line)),color='green')
AttributeError: 'PolynomialFeatures' object has no attribute 'fit_transofrm'

I dont know how to correct it. Hope someone can help. Thank you so much.

[v-deddai1-msft]

Hi @nabitti ,

Your issue is more related to python. I suggest you open a thread in python forumn in SO. People there will help you well. Please also refer to the similar post: https://stackoverflow.com/questions/56201362/polynomialfeatures-object-has-no-attribute-predict

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Best Regards,

Dedmon Dai