score function in linear regression model

[Thomas Passin]

There's a fairly good rundown of score() here:

"[Python/Sklearn] How does .score() works?"
https://www.kaggle.com/getting-started/27261

On 10/26/2022 2:18 AM, Fatemeh Heydari wrote:
> On Monday, October 24, 2022 at 7:14:10 AM UTC-7, Reto wrote:
>> On Sun, Oct 23, 2022 at 05:11:10AM -0700, Fatemeh Heydari wrote:
>>> model.score(X,Y)
>>
>> That will basically check how good your model is.
>>
>> It takes a bunch of X values with known values, which you provide in Y
>> and compares the output of model.Predict(X) with the Y's and gives you
>> some metrics as to how good that performed.
>>
>> In the case of linear regression that be R^2, the coefficient of determination
>> of the prediction.
>>
>> Cheers,
>> Reto
> 
> 
> Dear Reto
> Thanks for your attention. But I calculated R^2 for the model with the code : r2_score(predictedY,Y)
> and I got different result from the "score " function. I wish to know what mathematical formulation is behind this function
> 
> Thanks again