Re: FindRoot[] with mixed complex and real variables?

*To*: mathgroup at smc.vnet.net*Subject*: [mg79650] Re: FindRoot[] with mixed complex and real variables?*From*: chuck009 <dmilioto at comcast.com>*Date*: Wed, 1 Aug 2007 04:59:05 -0400 (EDT)

I made some syntax errors in my first reply. This is corrected and note how I'm back-substituting the results into the equations to check the results. Note that the the value calculated for x has an imaginary component on it. So need to work with it more. In[127]:= solutionSet = FindRoot[{(x + I*y)*BesselJ[1, x + I*y]* BesselK[0, I*t] == I*t*BesselK[1, I*t]* BesselJ[0, x + I*y], (x + I*y)^2 - t^2 == -200 + I*s, u*BesselJ[1, u]*BesselK[0, w] == w*BesselK[1, w]* BesselJ[0, u], u^2 + w^2 == g, u == x + I*y, w == I*t, g == -200 + I*s}, {{x, 2.39}, {y, 0.17}, {t, 14.34}, {s, 0.8}, {u, 2.39 + 0.17*I}, {g, -200 + 0.8*I}, {w, 14.34*I}}, MaxIterations -> 50, WorkingPrecision -> 15] {(x + I*y)*BesselJ[1, x + I*y]*BesselK[0, I*t] - t*BesselK[1, I*t]*BesselJ[0, x + I*y], (x + I*y)^2 - t^2 - (-200 + I*s), u*BesselJ[1, u]*BesselK[0, w] - w*BesselK[1, w]* BesselJ[0, u], u^2 + w^2 - g, u - (x + I*y), w - I*t, g - (-200 + I*s)} /. solutionSet