Re: Putting an If in my function

*To*: mathgroup at smc.vnet.net*Subject*: [mg101058] Re: [mg101039] Putting an If in my function*From*: Leonid Shifrin <lshifr at gmail.com>*Date*: Tue, 23 Jun 2009 07:03:32 -0400 (EDT)*References*: <200906220821.EAA09081@smc.vnet.net>

Hi, I would suggest that you use pattern - matching instead of If: Clear[fn]; fn[a_,g_,f_,x_,d_,w_]/;w==g:=d+a*f*x; fn[a_,g_,f_,x_,d_,w_]:= d (1+(Exp[g]-Exp[w])/f)^(f x)+(a (-1+(1+(Exp[g]-Exp[w])/f)^(f x)) f)/(Exp[g]-Exp[w]); Regards, Leonid On Mon, Jun 22, 2009 at 1:21 AM, Lobotomy <labbman at gmail.com> wrote: > Hi, this is my function > > #5 (1 + ((E^#2 - 1) - (E^#6 - > 1))/#3)^(#3*#4) + (#1*((1 + (((E^#2 - 1) - (E^#6 - > 1))/#3))^(#3*#4) - > 1))/(((E^#2 - 1) - (E^#6 - 1))/#3) &[a, g, f, x, d, w] > > > in the case when w==g the denominator equals zero. > > in this case i would like to rewrite the formula above to the much > simpler > d+a*n. How is this done? I've tried > > If[w == g, % = d + a*n], but this is not working. Another thing is > where to put the "If" > >

**References**:**Putting an If in my function***From:*Lobotomy <labbman@gmail.com>