function [SL1,SL2, Ratio_SL2_SL1] = comparestr(filename1, filename2, n)

% comparestr compares the polynomials made from filename1 (strplt type
% file) to filename 2 at 1 10 and 100 Amps
ff1=['S:\MagData\E163\quad\QE-N13\' filename1]
ff2=['S:\MagData\E163\quad\QE-N13\' filename2]
[p1_up,p1_down] = strnfit(ff1, n);

[p2_up,p2_down] = strnfit(ff2, n);

Imag = [1,10,20,40, 50,100]

SL1=polyval(p1_up,Imag)
SL2=polyval(p2_up,Imag)
format short g
Ratio_SL2_SL1 = SL2./SL1

% Ratio_SL2_SL1 - 1.0 
Pct= (Ratio_SL2_SL1 -1.0 ).*100.