a               = 6.60047    
b               = -2.81371   
c               = -7.50633   
d               = 3.73861    
e               = 1.63523   
f               = -1.22392  
g               = 0.316372  
h               = 0.699774  
j               = -0.041479  
k               = 0.00177354 
l = 0.001
m=0.01
set ytics -2,1
f(x)= a+b*(x-h)+c*(x-h)**2+d*(x-h)**3+e*(x-h)**4+f*(x-h)**5+g*(x-h)**6+j*(x-h)**7+k*(x-h)**8+l*(x-h)**9+ m*(x-h)**10
set grid
fit f(x) 'pulse.dat' u 1:2 via a,b,c,d,e,f,g,h, j,k,l,m
plot 'pulse.dat' u 1:2 ps 2 pt 4, f(x)