meta user
network profile
| bio | website | |
|---|---|---|
| location | China | |
| age | ||
| visits | member for | 1 year, 10 months |
| seen | 2 days ago | |
| stats | profile views | 15 |
I'm interested in data visualization, image processing, ODE/PDE, natural language processing, etc. Pardon my bad English, please :P
Email addr:
1:eJztk8ENwzAIRUkHyA5ZqdfeMkC6/605Vl8Gg8EykUD6imMb8/hxjvP7vl5EtN/63NpKpVIpqSgBg4XzKbwzvP6PJ/Baa2BvxMxzea1caV2al3zQnId7pHqS1yPsEkPPa8/Yk4c8MzmwjuSNtydp3DsHg/PMwov7o74/ntni4f6nSAbuXcPK8YzyYqy+16u8tnrmYYnq07LOee3pKcJrzX3XrHPnjdaz/if47NVqsWl4tBrJmalsPJF9ZegNYzVPKZ9+c/YGIg==
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Aug 23 |
comment |
Simplify $\tan^{-1}[(\cos x - \sin x)/(\cos x + \sin x)]$ define simplest please. |
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Jul 23 |
awarded | Supporter |
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Jul 3 |
awarded | Teacher |
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Jun 13 |
revised |
Compound Poisson process with exponential distribution added 12 characters in body |
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Jun 13 |
awarded | Editor |
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Jun 13 |
revised |
Compound Poisson process with exponential distribution added 10 characters in body |
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Jun 13 |
answered | Compound Poisson process with exponential distribution |
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Jul 21 |
revised |
Method for variable substitution in multiple summation added a tag |
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Jul 21 |
comment |
Method for variable substitution in multiple summation Yes they are:( I used one of the explicit sum formulas of Chebyshev polynomial (mathworld.wolfram.com/ChebyshevPolynomialoftheFirstKind.html eq.15), which introduces those floor functions. |
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Jul 21 |
comment |
Method for variable substitution in multiple summation @ Christian Blatter: Thanks very much for your answer. I understand the difficulties of counting lattice points in disk, but if considering the summation region bounded only by integer coefficients planes (like $\sum_k A_k x_k=B$ where $A_k, B\in \mathbb{Z}$), the problem might be much simpler and there might even exist a systematical technique for it. Besides, I'm thinking of using Iverson's bracket to avoid dealing with those tricky boundary conditions. |
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Jul 21 |
comment |
Method for variable substitution in multiple summation @Patrick Da Silva: Yes I draw 2-dim or 3-dim axes too when I do the transformation by hand :D But if I have many levels of sum, this will be inefficient cause it's hard to draw high dimension, and those floor and ceiling functions and steps$\neq 1$ are bothering. I think I need to treat the whole summation region as a high dimension polyhedron and find a systematical routine to deal with it. |
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Jul 21 |
awarded | Student |
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Jul 21 |
asked | Method for variable substitution in multiple summation |
