LogGamma[z] vs Log[Gamma[z]] behavior

*To*: mathgroup at smc.vnet.net*Subject*: [mg60915] LogGamma[z] vs Log[Gamma[z]] behavior*From*: "Alan" <info at optioncity.REMOVETHIS.net>*Date*: Mon, 3 Oct 2005 04:06:16 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Plotting these two for z = 1 + I y vs y is very instructive. I've had to write some pretty complicated code to make some other functions of mine continuous like LogGamma[] is. Can anyone think of some 'automatic' way to remove unwanted branch cut discontinuities in an arbitrary function of a complex argument? (More specifically, suppose I have a real integrand Re [f [c + I y] ], where c is fixed and y is the integration variable, and f is complicated and has unwanted discontinuities due to cuts. Since the integrator is adaptive ... ?) Thanks, alan