1,804 reputation
1932
bio website anhhuy.ch
location Switzerland
age 21
visits member for 3 years, 8 months
seen 10 hours ago

My name is Anh Huy Truong and I am currently studying mathematics at the ETH Zürich.


Jul
10
awarded  Nice Question
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awarded  Curious
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awarded  Inquisitive
May
15
awarded  Nice Question
Mar
21
awarded  Popular Question
Mar
17
awarded  Famous Question
Mar
16
awarded  Popular Question
Feb
19
accepted How can I find a non-negative interpolation function?
Feb
16
comment How can I find a non-negative interpolation function?
Do you have any idea what the constant you use to subtract depends on in order for the resulting function to being non-negative?
Feb
16
comment How can I find a non-negative interpolation function?
I was thinking about using the logarithm method after all by simply adding a constant to my values (e.g. $y_i + 1$) and then taking the logarithm. However, when I then take the exponential of the resulting interpolating polynomial, is there a formula to find the constant I have to subtract in order to get back? In the examples I tried out I could not find any regularity and most importantly the constant $-1$ does not work. :-(
Feb
16
comment How can I find a non-negative interpolation function?
I think the dirty solution will be best suited for my problem. I have values $y_i = 0$ which rules out taking the logarithm (or is there a solution for that issue?). However, if I am using Hermite interpolation (i.e. I want to interpolate derivatives as well), what values do I take for the derivatives? Simply the square roots?
Feb
15
asked How can I find a non-negative interpolation function?
Jan
14
asked How should I think about reflexive spaces? What “property” do I get from a space being reflexive?
Jan
8
accepted Why does $e_i \in \ell^2$ weakly converge to $0$?
Jan
7
asked Why does $e_i \in \ell^2$ weakly converge to $0$?
Jan
2
awarded  Favorite Question
Dec
13
accepted Showing that a matrix is positive (semi-)definite
Dec
9
comment Showing that a matrix is positive (semi-)definite
I'm sorry I didn't refer to the paper earlier. I asked for an alternative proof because the proof provided was not very intuitive to me, i.e. I would have never been able to come up with it. Since you came up independently with basically the same proof: Is there any logical reason for introducing that matrix and decomposing the matrix $D$ as in your answer? Is it just experience or is there a deeper reason? I have never seen this kind of decomposition yet which is why it was rather odd for me.
Dec
9
comment Showing that a matrix is positive (semi-)definite
@DavidSpeyer: I put it for completeness. Sorry if it confused anyone.
Dec
9
revised Showing that a matrix is positive (semi-)definite
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