I am beginning Mathematica user. Please show me the syntax on how to compute the following complex integral in Mathematica:

$\int_{|z-2i|=10} \frac{dz}{z(1-e^{-5z})}$

What I really want is a subroutine that takes $f$ - my function and $c$ - my circle and compute the following complex integral. Samples in documentation force me to alter $f$ every time. But calculation insets relies on residues, so I want to have clean syntax.

Thanks a lot for your help!

  • 1
    $\begingroup$ The documentation here has examples for Integral along a complex line, Along a piecewise linear contour in the complex plane and also Along a circular contour in the complex plane reference.wolfram.com/language/ref/Integrate.html $\endgroup$
    – Lotus
    May 18 '17 at 11:55
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    $\begingroup$ Hello. Thanks for the comment. I do not think your reference is practical. Imagine my that analytic express of $f$ has 30 instances of $z$. I do not want to covert every $z$ to parametric form. What I want is to have one unified function for different function $f$ and different contour $c$. $\endgroup$
    – Hedgehog
    May 18 '17 at 12:06
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    $\begingroup$ If you're actually computing residues, why not use Residue[]? $\endgroup$ May 18 '17 at 12:20
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    $\begingroup$ What code have you written for your f? $\endgroup$ May 18 '17 at 14:23
  • 3
    $\begingroup$ Possible duplicate of Paths integrals in the complex plane. Also this can be instructive How to calculate contour integrals with Mathematica? $\endgroup$
    – Artes
    May 18 '17 at 14:31

Try this:

    z = 2*I + 10*E^(I*t);
    NIntegrate[10/(z + (1 - E^(-5*z))), {t, 0, 2 \[Pi]}]

(*   2.07045 - 0.0177716 I  *)

Have fun!

  • $\begingroup$ Thanks for your reply. However, I do not need numeric value, I need symbolic one. $\endgroup$
    – Hedgehog
    May 18 '17 at 12:00
  • $\begingroup$ Then try Integrate instead, but I doubt that it will work. $\endgroup$ May 18 '17 at 12:14

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