Re: Solve InterpolatingFunction problem
- To: mathgroup at smc.vnet.net
- Subject: [mg31908] Re: Solve InterpolatingFunction problem
- From: "Jasem Mutlaq" <mutlaqja at ku.edu>
- Date: Tue, 11 Dec 2001 01:33:44 -0500 (EST)
- References: <9uss9d$cl6$1@smc.vnet.net> <9uvh0a$i18$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Thanks Brian! I already used FindRoot, and since there exists two roots that I wanted to obtain, I just plotted the curve and made the starting guess somewhere near the value of interest and was able to get pretty precise solutions! Regards, Jasem Mutlaq. "Brian Higgins" <bghiggins at ucdavis.edu> wrote in message news:9uvh0a$i18$1 at smc.vnet.net... > Jasem" use FindRoot instead of Solve . For example > > mySin = Interpolation[Table[{x, Sin[x]}, {x, 0, 5, .2}]]; > > In[4]:=FindRoot[mySin[x] == .5, {x, 1}] > > Out[4]={x -> 0.523618} > > Cheers, > > Brian > > "Jasem Mutlaq" <mutlaqja at ku.edu> wrote in message news:<9uss9d$cl6$1 at smc.vnet.net>... > > Hello. I obtained an interpolated function from a set of data representing a > > velocity curve (increasing & decreasing). I used the following > > > > vr =Interpolation[data]; > > Solve[vr[x]==0.6,x] > > > > InverseFunction::ifun: Inverse functions are being used. Values may be lost > > for multivalued inverses. > > Out[221]={{x->1. > > InverseFunction[InterpolatingFunction[{{0.,0.95}},<>],1,1][0.6]}} > > I'm expecting something like x = 3 or x = 9 (two solutions). > > > > Any suggestions are highly appreciated! > > > > Jasem Mutlaq. >