Why Cost Function for Linear Regression Is Always a Convex Shaped Function? The Next CEO of...
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Why Cost Function for Linear Regression Is Always a Convex Shaped Function?
The Next CEO of Stack OverflowGradient Descent on Non-Convex Function Works But How?Machine learning Linear regression cost functionLogistic regression: Prove that the cost function is convexLinear Regression: linear or reciprocal function?Why using squared distances in the cost function (Linear Regression)?Machine Learning Linear Regression Cost Function NotationLogistic Regression: When can the cost function be non-convex?Minimum sample sizes needed for a series of allowed errors, given a required accuracy and required confidencewhy is the least square cost function for linear regression convexFunky change in correlation
$begingroup$
This diagram is from Andrew Ng course for ML/DL:
enter image description here
But isn't the cost function (least squares function) shape depends on scatter of the data ?
For example below, the minimum will be at (0,1):
enter image description here
that doesn't correspond to convex shape (if you will imagine it in 3d plot), that Andrew Ng showed above.
UPDATE
Oh, i think I understand... my example is a convex shape too, but simply shifted by coordinates, relatively to the Andrew's example.
Am i right?
statistics statistical-inference machine-learning least-squares linear-regression
$endgroup$
add a comment |
$begingroup$
This diagram is from Andrew Ng course for ML/DL:
enter image description here
But isn't the cost function (least squares function) shape depends on scatter of the data ?
For example below, the minimum will be at (0,1):
enter image description here
that doesn't correspond to convex shape (if you will imagine it in 3d plot), that Andrew Ng showed above.
UPDATE
Oh, i think I understand... my example is a convex shape too, but simply shifted by coordinates, relatively to the Andrew's example.
Am i right?
statistics statistical-inference machine-learning least-squares linear-regression
$endgroup$
1
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39
add a comment |
$begingroup$
This diagram is from Andrew Ng course for ML/DL:
enter image description here
But isn't the cost function (least squares function) shape depends on scatter of the data ?
For example below, the minimum will be at (0,1):
enter image description here
that doesn't correspond to convex shape (if you will imagine it in 3d plot), that Andrew Ng showed above.
UPDATE
Oh, i think I understand... my example is a convex shape too, but simply shifted by coordinates, relatively to the Andrew's example.
Am i right?
statistics statistical-inference machine-learning least-squares linear-regression
$endgroup$
This diagram is from Andrew Ng course for ML/DL:
enter image description here
But isn't the cost function (least squares function) shape depends on scatter of the data ?
For example below, the minimum will be at (0,1):
enter image description here
that doesn't correspond to convex shape (if you will imagine it in 3d plot), that Andrew Ng showed above.
UPDATE
Oh, i think I understand... my example is a convex shape too, but simply shifted by coordinates, relatively to the Andrew's example.
Am i right?
statistics statistical-inference machine-learning least-squares linear-regression
statistics statistical-inference machine-learning least-squares linear-regression
edited May 31 '18 at 21:12
Royi
3,59012354
3,59012354
asked Mar 8 '18 at 17:31
up-to-youup-to-you
84
84
1
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39
add a comment |
1
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39
1
1
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Because the cost function is given by:
$$ frac{1}{2} left| X theta - y right|_{2}^{2} $$
Which is a Linear Regression Problem with the Least Squares cost function which is a Convex Function of $ theta $.
$endgroup$
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation||is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!
$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
add a comment |
Your Answer
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Because the cost function is given by:
$$ frac{1}{2} left| X theta - y right|_{2}^{2} $$
Which is a Linear Regression Problem with the Least Squares cost function which is a Convex Function of $ theta $.
$endgroup$
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation||is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!
$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
add a comment |
$begingroup$
Because the cost function is given by:
$$ frac{1}{2} left| X theta - y right|_{2}^{2} $$
Which is a Linear Regression Problem with the Least Squares cost function which is a Convex Function of $ theta $.
$endgroup$
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation||is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!
$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
add a comment |
$begingroup$
Because the cost function is given by:
$$ frac{1}{2} left| X theta - y right|_{2}^{2} $$
Which is a Linear Regression Problem with the Least Squares cost function which is a Convex Function of $ theta $.
$endgroup$
Because the cost function is given by:
$$ frac{1}{2} left| X theta - y right|_{2}^{2} $$
Which is a Linear Regression Problem with the Least Squares cost function which is a Convex Function of $ theta $.
answered Mar 16 '18 at 15:43
RoyiRoyi
3,59012354
3,59012354
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation||is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!
$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
add a comment |
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation||is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!
$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Can you please add more details to your answer? Thank you!
$endgroup$
– Alex Yursha
Oct 10 '18 at 1:58
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
Could you point me what would you like to be extended?
$endgroup$
– Royi
Oct 10 '18 at 14:32
$begingroup$
The notation
|| is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation
|| is not familiar to me. Perhaps, at least provide links to supplemental resources of your choice, which will help to interpret the formula you wrote. Thank you!$endgroup$
– Alex Yursha
Oct 14 '18 at 5:52
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
$begingroup$
The notation $ left| cdot right| $ stands for norm. So the $ {left| cdot right|}_{2} $ stands for the $ {L}_{2} $ norm and $ {left| cdot right|}_{2}^{2} $ is the $ {L}_{2} $ norm squared.
$endgroup$
– Royi
Oct 14 '18 at 6:04
add a comment |
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1
$begingroup$
the cost function should be convex, which corresponds roughly to a "bow" shape
$endgroup$
– Tony S.F.
Mar 8 '18 at 17:34
$begingroup$
sorry, updating question
$endgroup$
– up-to-you
Mar 8 '18 at 17:39