# Interpolation undefined on domain

I have made an interpolation of two variables of a fairly large set of numbers imported from a file (4 million lines in an .m file written out with C++).

The ranges of the two parameters is 0 to 2.5 and 0 to 60, respectively, so I am confused why the interpolation for certain ranges inside 0:2.5, 0:60 , seen most clearly when plotting.

When evaluating in one of these undefined ranges, for example 0.2, 0.2 it takes many seconds before finally outputting something like this.

0.030098 +
0.005752199999999999 (1.8894271781617253 -
0.009955999999999993 (22.098356216511277 +
0.0214602 (-55.4176617318362 -
0.025663999999999992 (-1495.3986641465997 +
0.03716810000000001 (10148.485672332376 -
0.04137199999999999 (61777.19935813235 +
0.0528761 (-818590.1061571125 -
0.05707999999999999 (-15.915482422145436 \
(818590.1061571125 -
12.73234946224922 (-10343.382090047433 -
21.220654487425698 (-7724.724645111078 -
10.61029347010709 (865.1929296352522 -
31.83091418385536 (21.333461835452677 -
9.094538638602133 (-15.74708850390108 -
63.66182836771069 (-1.7906312792105215 -
7.9577222134245185 (-5.197116 +
2.53974 e))))))))))))))))


It seems that e is undefined, so why would Mathematica use it automatically?

If I manually set e = E, then I can evaluate the above lines, but the function is still unwilling to be plotted on some ranges (takes several minutes of "running" after which is stops with \$Aborted message).

Could it be that I should simply not use Interpolation for files that big?

• Found out it was the way that the .m file was being written. It writes scientific as 5e-5 for instance, whereas Mathematica would write 5*^-5 so the error was on my part. Not sure if the post should be deleted then? Commented Mar 27, 2017 at 9:02
• Import[] can handle exponential notation: ImportString["2e-5,3e-4\n0.4,0.1", "CSV"]. Commented Mar 27, 2017 at 9:14
• @KasparH, you could self answer your question or delete it. Commented Mar 27, 2017 at 9:50

Found out it was the way that the .m file was being written. It writes scientific as 5e-5 for instance, whereas Mathematica would write 5*^-5` so the error was on my part. Posted anyway to potentially help other clueless people like me.