Hello, Paul,

Thank you for the reply! Now I know the reason why it's shifted. I didn't

understand it well.

However, I don't understand yet why lammps doesn't use a simple linear

interpolation for

the keyword 'linear'? If we could have that large amount of input data, I

expect a simple

linear interpolation gives a better fitting. Due to the splining, both

'spline' and 'linear' table

style do not produce a fitted curve exactly crossing all the original data

points. You can

see this if you zoom in the plot even you think the fitting is good enough.

The simplest

linear interpolation can at least pass all the original data points, which

should be trusted

for a known function or when you trust your input data. For unknown function

form, we

cannot say the original data are always trustable than the fitted ones. But

I don't see

a way to do this in lammps. (lookup method is not good, it makes step

function.)

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