Trace of disturbance vector squared












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I was reading Jushan Bai's paper (2009) and came across the least squares objective function is as follows: tr[(W-FA')(W-FA')'] from W = FA'+ e on page 1236.



I am sorry about my notation since I do not know how
to write Greek letters here (A should be like Lamda)



That function seems strange to me since the residual sum of squares would be the choice for the function for me and I see if he considered RSS, RSS could be written as tr(W'MfW) on the next line on the paper, where Mf is the projection matrix.



But his objective function considers the squared disturbance and there, I don't even understand why the transpose mark is attached like ee', not like e'e
which is more similar to RSS, I guess...



Could please anyone help me with this?
Thanks a lot in advance.










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  • $begingroup$
    A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
    $endgroup$
    – hardmath
    Dec 18 '18 at 5:35
















0












$begingroup$


I was reading Jushan Bai's paper (2009) and came across the least squares objective function is as follows: tr[(W-FA')(W-FA')'] from W = FA'+ e on page 1236.



I am sorry about my notation since I do not know how
to write Greek letters here (A should be like Lamda)



That function seems strange to me since the residual sum of squares would be the choice for the function for me and I see if he considered RSS, RSS could be written as tr(W'MfW) on the next line on the paper, where Mf is the projection matrix.



But his objective function considers the squared disturbance and there, I don't even understand why the transpose mark is attached like ee', not like e'e
which is more similar to RSS, I guess...



Could please anyone help me with this?
Thanks a lot in advance.










share|cite|improve this question









$endgroup$












  • $begingroup$
    A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
    $endgroup$
    – hardmath
    Dec 18 '18 at 5:35














0












0








0





$begingroup$


I was reading Jushan Bai's paper (2009) and came across the least squares objective function is as follows: tr[(W-FA')(W-FA')'] from W = FA'+ e on page 1236.



I am sorry about my notation since I do not know how
to write Greek letters here (A should be like Lamda)



That function seems strange to me since the residual sum of squares would be the choice for the function for me and I see if he considered RSS, RSS could be written as tr(W'MfW) on the next line on the paper, where Mf is the projection matrix.



But his objective function considers the squared disturbance and there, I don't even understand why the transpose mark is attached like ee', not like e'e
which is more similar to RSS, I guess...



Could please anyone help me with this?
Thanks a lot in advance.










share|cite|improve this question









$endgroup$




I was reading Jushan Bai's paper (2009) and came across the least squares objective function is as follows: tr[(W-FA')(W-FA')'] from W = FA'+ e on page 1236.



I am sorry about my notation since I do not know how
to write Greek letters here (A should be like Lamda)



That function seems strange to me since the residual sum of squares would be the choice for the function for me and I see if he considered RSS, RSS could be written as tr(W'MfW) on the next line on the paper, where Mf is the projection matrix.



But his objective function considers the squared disturbance and there, I don't even understand why the transpose mark is attached like ee', not like e'e
which is more similar to RSS, I guess...



Could please anyone help me with this?
Thanks a lot in advance.







statistics






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share|cite|improve this question











share|cite|improve this question




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asked Dec 18 '18 at 5:05









June ParkJune Park

11




11












  • $begingroup$
    A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
    $endgroup$
    – hardmath
    Dec 18 '18 at 5:35


















  • $begingroup$
    A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
    $endgroup$
    – hardmath
    Dec 18 '18 at 5:35
















$begingroup$
A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
$endgroup$
– hardmath
Dec 18 '18 at 5:35




$begingroup$
A brief introduction to posting mathematical notation may be of interest to you. It has links to more detailed information.
$endgroup$
– hardmath
Dec 18 '18 at 5:35










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