Help writting a simple code!
显示 更早的评论
I'm trying to make a Simulink model consisting of a clock (as a source) and a MATLAB function that calculates the following:
Y=exp(t) * sigma(n=1:inf)[n * exp(n*t)]
Can anybody help me write the code?
回答（5 个）
Paulo Silva
2011-6-29
MATLAB Fcn
exp(u)*sum([1:10].* exp([1:10].*u)) %not infinite sum but close enough
C.J. Harris
2011-6-29
0 个投票
You won't be able to write an infinite series directly. You will either have to use an approximation, or only calculate the sum for the first 'n' elements.
Walter Roberson
2011-6-29
If and only if t is less than 0,
Y = exp(2*t)/(exp(t)-1)^2
That is, sum(n*exp(n*t), n = 1 .. infinity) is exp(t)/(exp(t)-1)^2
If t is 0 or greater, the sum is infinite, as you are adding together numbers that increase infinitely.
Hossein sadri
2011-6-30
0 个投票
2 个评论
Paulo Silva
2011-6-30
[1:10].^2
Walter Roberson
2011-6-30
n.^2 instead of n^2
But n^2*exp(u) has the same problem I described above of having an infinite value unless u is negative.
amey
2011-7-1
0 个投票
n=1:1:100; y=exp(0.4)*(n.*exp(0.4*n)); tot=0; for i=1:100; tot=tot+y(i); end disp(tot);
2 个评论
amey
2011-7-1
u = 0.4 ; % assumed
n=1:1:100; % only first 100 terms taken
Paulo Silva
2011-7-1
is there another question for us?
类别
在 帮助中心 和 File Exchange 中查找有关 Entering Commands 的更多信息
2011-6-29
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
