Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
In article <Pine.SOL.3.95.970603185017.6133C-100000@comp>, Brent Ragar <bragar@comp.uark.edu> writes: > After several replies to my earlier question (for which I am most > grateful), it was suggested that I post my problem to the group for > everyone to "have a crack at it." Apparently some people enjoy this kind > of thing. :^) > I am trying to solve for the value x in an equation similar to the > one below (note, integer on left-hand side of = sign is not necessarily > going to be 1 and ln stands for the natural log): > > 1 = (ln(1-X))/(ln(1+x)) > > Since I can't isolate the x, I can't take the easy way out and > just define the variable like I have been doing. It has been suggested > that another program might be easier or even necessary, but I just wanted > to make sure that I exhausted all my possibilities with IDL before I move > on. Thanks a lot for your time... > There is a routine in my library, name ROOT, which will find the roots of anything that can be written as an IDL function. Handles multiple roots too. Your function is relatively simple, shouldn't be any problem. If you are interested, do anonymous FTP to cars3.uchicago.edu. Once you've logged in, change directory down to MIDL. The routine is there. NOw, I suggest downloading everything in sight (eighty something routines) since most of them call one another thus if you get just a partial set, it may not work. And, you may find other interesting goodies there. Mati Meron | "When you argue with a fool, meron@cars.uchicago.edu | chances are he is doing just the same"