How can I plot 3 defined variables on a loglog scale with 2 x-axis with same y-axis.

load Cmp2.txt;
p= Cmp2(:,1);
u= Cmp2(:,2);
h=(p/(9.8*1000));
ii=(h/0.0011);
K=(u./ii);
Re=(1000*u*4e-4)/(0.001);
loglog(ii,K,'o') %This is the plot that I would like to add the third variable (Re).
title('K vs i'), xlabel('i (-)'), ylabel('K (m/s)')
axis([1e-5,10,0.15,0.5]);
%How Can alter the third x axis parameters/limits to fit the data better?

[dpb]

What do you want plotted, specifically? Need the data to be able to see what you've got.

Certainly it's possible to have two x-axes similar to two y-axes. TMW built yyaxis for the latter; hard to understand why they didn't go ahead with x as well, but there's example of what to do specifically and I suspect somebody else has been fed up enough to have posted a routine on the File Exchange.