How to equally balance $|X|_1$ over the columns of $X$?











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I have the following optimization



$$min_X f(X)+lambda |X|_1,$$
in which $Xin mathbb{R}^{n times k}$, and $|X|_1=sum_{i,j} |x_{ij}|$, and $f(X)$ is differentiable in $X$.



It is ideal for me to have a small value for $|X|_1$ which is equally balanced over the columns of $X$.



For example, I like to have $|X_{:,i}|_1 approx |X_{:,j}|_1~forall i,j$, where $X_{:,i}$ denotes colimn $i$ of $X$.



Specifically, I want to prevent situations in which $X$ has a few columns with large entries and a lot of columns with very small entries, assuming $f(X)$ allows those situations.










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  • you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
    – LinAlg
    14 hours ago










  • @LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
    – Babak
    13 hours ago






  • 1




    that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
    – LinAlg
    13 hours ago















up vote
0
down vote

favorite












I have the following optimization



$$min_X f(X)+lambda |X|_1,$$
in which $Xin mathbb{R}^{n times k}$, and $|X|_1=sum_{i,j} |x_{ij}|$, and $f(X)$ is differentiable in $X$.



It is ideal for me to have a small value for $|X|_1$ which is equally balanced over the columns of $X$.



For example, I like to have $|X_{:,i}|_1 approx |X_{:,j}|_1~forall i,j$, where $X_{:,i}$ denotes colimn $i$ of $X$.



Specifically, I want to prevent situations in which $X$ has a few columns with large entries and a lot of columns with very small entries, assuming $f(X)$ allows those situations.










share|cite|improve this question
























  • you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
    – LinAlg
    14 hours ago










  • @LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
    – Babak
    13 hours ago






  • 1




    that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
    – LinAlg
    13 hours ago













up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have the following optimization



$$min_X f(X)+lambda |X|_1,$$
in which $Xin mathbb{R}^{n times k}$, and $|X|_1=sum_{i,j} |x_{ij}|$, and $f(X)$ is differentiable in $X$.



It is ideal for me to have a small value for $|X|_1$ which is equally balanced over the columns of $X$.



For example, I like to have $|X_{:,i}|_1 approx |X_{:,j}|_1~forall i,j$, where $X_{:,i}$ denotes colimn $i$ of $X$.



Specifically, I want to prevent situations in which $X$ has a few columns with large entries and a lot of columns with very small entries, assuming $f(X)$ allows those situations.










share|cite|improve this question















I have the following optimization



$$min_X f(X)+lambda |X|_1,$$
in which $Xin mathbb{R}^{n times k}$, and $|X|_1=sum_{i,j} |x_{ij}|$, and $f(X)$ is differentiable in $X$.



It is ideal for me to have a small value for $|X|_1$ which is equally balanced over the columns of $X$.



For example, I like to have $|X_{:,i}|_1 approx |X_{:,j}|_1~forall i,j$, where $X_{:,i}$ denotes colimn $i$ of $X$.



Specifically, I want to prevent situations in which $X$ has a few columns with large entries and a lot of columns with very small entries, assuming $f(X)$ allows those situations.







linear-algebra optimization convex-optimization






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share|cite|improve this question













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share|cite|improve this question








edited 13 hours ago

























asked 15 hours ago









Babak

297110




297110












  • you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
    – LinAlg
    14 hours ago










  • @LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
    – Babak
    13 hours ago






  • 1




    that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
    – LinAlg
    13 hours ago


















  • you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
    – LinAlg
    14 hours ago










  • @LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
    – Babak
    13 hours ago






  • 1




    that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
    – LinAlg
    13 hours ago
















you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
– LinAlg
14 hours ago




you could have a different $lambda$ for each column, and keep adjusting $lambda$ until you are satisfied
– LinAlg
14 hours ago












@LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
– Babak
13 hours ago




@LinAlg yes, but it would not be easy especially when $k$ is large (e.g 100 or more)
– Babak
13 hours ago




1




1




that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
– LinAlg
13 hours ago




that the problem is not easy is to be expected, since setting a lower bound on a norm is difficult from an optimization perspective
– LinAlg
13 hours ago















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