I am using Wolfram Mathematica 11. Given these quantities: v = 3; Y = Sqrt[v^2 - X^2]; Ja = BesselJ[0, X]; Jap = -BesselJ[1, X]; Ka = BesselK[0, Y]; Kap = -BesselK[1, Y]; side1 = Jap / (X*Ja); side2 = -Kap / (Y*Ka); I would like to obtain the same visual output as: Plot[{side1, side2}, {X, 0, 10}] but on a `.txt` file, simply containing a table of values in this notation: 0.0000000000e+00 -inf -inf 3.0060120240e-02 -2.3042094212e+00 -2.1217639107e+01 6.0120240481e-02 -1.8613440179e+00 -1.0654661322e+01 First column should list the `X` values; second column should list the corresponding `side1` values; third column the corresponding `side2` values. How is it possible, with and without adaptive sampling? **Important note**: I am not obliged to use `Plot`. I would like to obtain a `.txt` output file with the lines in the same format as above. The way it is created (through `Plot` or *any* other suitable function) is not important. ---------- This is my naive attempt to adapt code from [this answer][1], at least for the plot of the first function `side1`: data = Cases[Plot[side1@X, {X, 0, 10}], Line[data_] :> data, -4, 1][[1]]; Export["file.txt", data, "Table"] but it generates an error: Part: Part 1 of {} does not exist [1]: https://mathematica.stackexchange.com/a/19860