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dwi
Posts:
17
Registered:
10/18/12


Re: sum of exponentials
Posted:
Nov 24, 2012 7:16 PM


"Roger Stafford" wrote in message <k8r036$nn7$1@newscl01ah.mathworks.com>... > "dwi" wrote in message <k8qlsv$ktj$1@newscl01ah.mathworks.com>... > > Ok, I understand now how this works. But still, you said the result will be > > x(3)+x(2)*e^(1)+x(1)*e^(2))/(1+e^(1)+e^(2)); > > while I want > > (x(3)*e^(1)+x(2)*e^(2)+x(1)*e^(3))/(e^(1)+e^(2)+e^(3)); > > Also, how would your code change if I had e^(1/20), e^(2/20), e^(3/20) etc? >         > The two expressions > > (x(3)*e^(1)+x(2)*e^(2)+x(1)*e^(3))/(e^(1)+e^(2)+e^(3)) > > and > > (x(3)+x(2)*e^(1)+x(1)*e^(2))/(1+e^(1)+e^(2)) > > > are identically equal. Just divide the numerator and denominator of the first expression by e^(1) to get the second expression. What you want and what this code produces are the same thing. > > As to your second question, just the two lines > > a = x(k) + a*f*e^(1); > b = 1 + b*f*e^(1); > > would need to be changed to: > > a = x(k) + a*f*e^(1/20); > b = 1 + b*f*e^(1/20); > > Roger Stafford Ok, thank you!



