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# Play safe
free @all
###################################################
# Simple straight line fit example
###################################################
# First load gnuplot macros (should be your .fudgitrc)
# that will be used below.
load fudgitrc
# Read in the following numbers in vectors X and Y:
read - X:1 Y:2
0.050000 -8.3435253e-15
0.100000 -7.3682587e-08
0.150000 -2.62540725e-05
0.200000 -0.000495454499
0.250000 -0.00288394212
0.300000 -0.00930746938
0.350000 -0.0214061842
0.400000 -0.0397837034
0.450000 -0.06410238
0.500000 -0.0934515401
0.550000 -0.126705137
0.600000 -0.162760493
0.650000 -0.2006568
0.700000 -0.239611356
0.750000 -0.279012309
0.800000 -0.318394131
0.850000 -0.357409756
0.900000 -0.395805282
0.950000 -0.433398977
1.000000 -0.470064566
1.050000 -0.505718175
1.100000 -0.540308208
end
# Transform first column to -1/(first column)
let X = -1/X
# Take the ln(-1/Y) of the second column
let Y = ln(-1/Y)
# Fit a straight line
set function straight
# Using least square regression
set method ls_reg
# We need 2 parameters, called them, say, A[1] and A[2].
set parameter A 2
# Do the fit:
fit X Y
# Show results:
echo
echo Fit results: A[1] + A[2]*X
show parameters
# Start a new plot
ResetPlot
# Give some titles and labels
title "A fit example"
xlabel "-1/T"
ylabel "ln(tau)"
# Plot data points with a key:
tpplot X Y "experimental"
# Plot fit to it using a solid line and a key:
tlplot X YFIT "This is the fit"
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