Bug introduced in 11.3

I recently updated to 11.3 and found that my FITS files don't import the same way anymore. I've read a posts about the changes made to FITS imports and can deal with that fine but it seems that it has also affected my raw data values.

Using version 11.1.1

Import["ckp00_7250.fits", "RawData"][[2]][[400]]

{4350., 0., 3.432*10^7, 3.251*10^7, 3.056*10^7, 2.879*10^7, 2.742*10^7, 2.63*10^7, 2.531*10^7, 2.449*10^7, 2.382*10^7, 2.331*10^7}

Using version 11.3

Import["ckp00_7250.fits", "RawData"][[2]][[400]]

{4350., 0., 3.43207, 3.25107, 3.05607, 2.87907, 2.74207, 2.6307, 2.53107, 2.44907, 2.38207, 2.33107}

The 11.1.1 output is correct. The 11.3 output looks like it took the *10^ and made it into a 0.

How am I supposed to fix this? Here is a link to the fits file I am using.


  • 1
    $\begingroup$ I downloaded your file and imported it in MMA 11.2; data = Import[filename, "RawData"] returns a list with dimensions {1, 12, 1222}, so trying to extract part 2 from it fails. I can reproduce your data using data[[1, All, 401]] though; the number values are the same you get in MMA 11.1. $\endgroup$ – MarcoB Apr 2 '19 at 22:40
  • $\begingroup$ Thanks for taking a look! If I just do Import["ckp00_7250.fits", "RawData"] in 11.3 I get <|1 -> Missing["NotAvailable"], 2 -> {{90.9, 0., 0 ... wheras in 11.1.1 I get {None, {{90.9000015259, 0., 0. ... $\endgroup$ – jmadden Apr 3 '19 at 1:24

We have confirmed this is a bug in 11.3. This issue is already resolved in upcoming versions of Mathematica. In the meantime, I suggest to try a hidden element "RawDataLegacy" which preserves the behavior from before the refactor to Associations. These elements will no longer be accessible in versions past 11.3, I strongly encourage you to check out the updates in coming versions as there have been many active improvements to FITS.

  • $\begingroup$ Okay thanks! I've reverted back to 11.1.1 for the time being. I'll keep an eye out for updates. $\endgroup$ – jmadden Apr 3 '19 at 21:49
  • 1
    $\begingroup$ Just wanted to document an update to this question. This issue appears to be fixed as of version 12.0. The result is now the same as in 11.1.1 which is what the output should be. Thanks all! $\endgroup$ – jmadden Apr 24 '19 at 18:02

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