Imported csv file plotting incorrect values

Found a bug? Tell us about it here

Moderator: DPlotAdmin

Post Reply
kberger
Posts: 1
Joined: Thu Nov 08, 2018 9:16 am

Imported csv file plotting incorrect values

Post by kberger »

When I import a csv file with some very small numbers (see below), instead of plotting the first column against the second I get a plot of the line number against the first column. I've tried importing the file via drag and drop, as well as just copy-pasting the values. The issue seems to go away if I replace the very small values with 0 and I can certainly keep that in mind for the future, but this seems like very odd behavior. I tried replacing just some of the values with 0, and eventually I can get it to import correctly with a few of these non-zero values but the actual number seems inconsistent. I'm on version 2.3.5.7.

0,0
0.01,7.77313e-320
0.02,1.55433e-319
0.03,2.33115e-319
0.04,3.10772e-319
0.05,3.884e-319
0.06,4.65993e-319
0.07,5.43546e-319
0.08,6.21055e-319
0.09,6.98515e-319
0.1,7.7592e-319
0.11,8.53266e-319
0.12,9.30548e-319
0.13,1.00776e-318
0.14,1.0849e-318
0.15,1.16196e-318
0.16,1.23893e-318
0.17,1.31582e-318
0.18,1.39261e-318
0.19,1.46931e-318
0.2,1.54591e-318
0.21,1.62241e-318
0.22,1.6988e-318
0.23,1.77507e-318
0.24,1.85122e-318
0.25,1.92726e-318
0.26,2.00316e-318
0.27,2.07893e-318
0.28,2.15456e-318
0.29,2.23005e-318
0.3,2.30539e-318
0.31,2.38058e-318
0.32,2.45561e-318
0.33,2.53048e-318
0.34,2.60518e-318

Thanks for the help.
User avatar
DPlotAdmin
Posts: 2312
Joined: Tue Jun 24, 2003 9:34 pm
Location: Vicksburg, Mississippi
Contact:

Post by DPlotAdmin »

You've run into the limits of double precision (8 byte) floating point numbers. The smallest number that can be represented is ~1.1E-308.

Rather than trying to parse numbers in text files (which would slow the file-reading process to a crawl), DPlot reads those text representations of numbers directly into... well, numbers. So the results in your case will at best be unpredictable. I'm actually surprised it didn't crash.
Visualize Your Data
support@dplot.com
Post Reply