Steve@ Posted January 31, 2019 Share Posted January 31, 2019 Hello, I need your help to calculate (approximate) a double series as shown in the attached. Thank you so much. Best, Steve.double_series.pdf Link to comment Share on other sites More sharing options...
mathematic Posted January 31, 2019 Share Posted January 31, 2019 Without any information about f(i), it can't be done. Link to comment Share on other sites More sharing options...
Steve@ Posted February 1, 2019 Author Share Posted February 1, 2019 Hello mathematic, The function f(i) = |2*i - A|, A is a constant. Best, Steve. double_series.pdf Link to comment Share on other sites More sharing options...
mathematic Posted February 1, 2019 Share Posted February 1, 2019 (edited) In the denominator does 2^k multiply j or j+i? Edited February 1, 2019 by mathematic structure Link to comment Share on other sites More sharing options...
Steve@ Posted February 2, 2019 Author Share Posted February 2, 2019 [(2^k multiply j) + i] in the denominator. Link to comment Share on other sites More sharing options...
mathematic Posted February 2, 2019 Share Posted February 2, 2019 (edited) On 2/2/2019 at 10:13 PM, mathematic said: [math]\sum_{i=1}^n\sum{j=1}^n\frac{|2i-A|}{2^kj+i}=\sum_{i=1}^n\frac{|2i-A|}{2^k}\sum{j=1}^n\frac{1}{j+2^{-k}i}\approx \sum_{i=1}^n\frac{|2i-A|}{2^k}(ln{n+2^{-k}i})-ln(2^{-k}i))[/math]. See if you can start here. I am trying to use Latex - not working. Edited July 7, 2019 by Strange latex problem Link to comment Share on other sites More sharing options...
Steve@ Posted February 7, 2019 Author Share Posted February 7, 2019 Hello everyone, Is there any update for this problem? Best regards, Link to comment Share on other sites More sharing options...
mathematic Posted February 7, 2019 Share Posted February 7, 2019 I can't get at my last post to try to fix it. Essentially I tried to rearrange things so that the j summation could be carried out. Link to comment Share on other sites More sharing options...
mathematic Posted February 8, 2019 Share Posted February 8, 2019 (edited) Try this website. You are more likely to get a response. Advise - they have a lot of nitpickers, so define the question as clearly as possible and avoid linking to somewhere else if you can. https://math.stackexchange.com Edited February 8, 2019 by mathematic remove underline Link to comment Share on other sites More sharing options...
Steve@ Posted February 8, 2019 Author Share Posted February 8, 2019 Thank you so much. If you have any update, let me know. I'm very appreciated to get your help. Link to comment Share on other sites More sharing options...
MotleyNoumenon Posted July 7, 2019 Share Posted July 7, 2019 First I was wondering by what calculate means, but eitherway i dont think there is a closed form. Link to comment Share on other sites More sharing options...
Strange Posted July 7, 2019 Share Posted July 7, 2019 On 2/7/2019 at 10:10 PM, mathematic said: I can't get at my last post to try to fix it. Essentially I tried to rearrange things so that the j summation could be carried out. I think I fixed your Latex (no idea if it is correct or not!) Link to comment Share on other sites More sharing options...
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