FIT_MAXITER = 10
set angles radians
s(x) = a * sin(2*pi*f/10000*x - p ) + o
f = 200
a = 400
o = 513
p = 1
fit [0:60] s(x) 'dds_ref.dat' using (column(1)/3.0):(column(2)/4) via p
fit [0:60] s(x) 'dds_ref.dat' using (column(1)/3.0):(column(2)/4) via p,a
fit [0:60] s(x) 'dds_ref.dat' using (column(1)/3.0):(column(2)/4) via p,a,o
FIT_MAXITER = 10
fit s(x) 'dds_ref.dat' using (column(1)/3.0):(column(2)/4) via p,a,o,f
#plot [0:200] "dds_ref.dat" using (column(1)/3.0):(column(2)/4) with linespoints, s(x)
#pause -1