How to read long numbers?

Question

Now, I have a data file (abc.dat) and it includes many long-Fortran-like numerical numbers as follows,

 6.329743394299864138426200801048403E-0008
-2.549598515596261539775494416553164E-0005
-4.070996338361811028817170114484442E-0005

How to read these data in Mathematica? If we use ReadList["abc.dat",Real] and it is not available for these long numbers. If we use ReadList["abc.dat", Record], then we need to find a way to change the string to numbers. Is there some better way for dealing with this problem ?

Read as text, then use something like ToExpression[StringReplace[nums, "E" -> "*10^"]] on that list. However, ReadList[...,Number] should handle the Fortran style. — ciao, Apr 05 '14 at 06:27
Related http://mathematica.stackexchange.com/questions/33498/readlist-cant-read-from-file-containing-high-precision-reals — ciao, Apr 05 '14 at 06:51
In version 7 ReadList["abc.dat", Real] appears to work correctly, yielding: {6.32974339429986413842620080104840*10^-8, -0.0000254959851559626153977549441655316, -0.0000407099633836181102881717011448444}. What output do you get? — Mr.Wizard, Apr 05 '14 at 06:53
Also related: How to convert a string of number into real numbers without precision loss — Mr.Wizard, Apr 05 '14 at 06:54
@rasher Wait, I think I misunderstood; you think this is not a bug then? — Mr.Wizard, Apr 05 '14 at 18:07
@Mr.Wizard: No, I think it is, but I'm loath to call something a bug publicly without others reproducing/confirming it first. — ciao, Apr 05 '14 at 21:34

Coolwater · Answer 1 · 2014-04-05T07:00:55.907

1

I opened HxD and pasted your numbers and saved as abc.dat. Then this worked for (8.0.4.0):

Import["C:\\f1\\f2\\Desktop\\abc.dat"]
(*{{6.32974339429986413842620080104840\[CenterDot]10^-8},{-0.0000254959851559626153977549441655316},{-0.0000407099633836181102881717011448444}}*)

edited Apr 05 '14 at 07:00

answered Apr 05 '14 at 06:28

Coolwater

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Incidentally in version 7 Import does not work fully here: data is imported as machine reals, losing input precision. – Mr.Wizard Apr 05 '14 at 06:59

How to read long numbers?

1 Answers1