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Reporting NCL bugs

[Using ftp to upload data/scripts | Known bugs]

NCL has a long and successful track record of user support. The NCL project wants to help users but our time is valuable too!

The NCL project gets many statements/questions to the effect that "Something is wrong", "the results don't agree with ...", etc.

Most often the problems are due to users not reading the documentation.

Bug reports should be emailed to ncl-talk. Before sending us any code, data, and/or image files, however, please read these posting guidelines first.

To summarize:

  • Carefully read any error messages.
  • Read and re-read the documentation for any functions being used.
  • Use simple procedures like printVarSummary, printMinMax, and print to examine data.
  • Make sure data has the correct units required.
  • Make sure your data doesn't have unexpected missing values.
  • Make sure your data doesn't need to have a scale factor and/or offset applied.
  • Examine a file's contents via "ncl_filedump" or "ncdump -h" ("ncdump" is for NetCDF files only).

Only after doing the above should the script, data, and/or image files be sent to to ncl-talk.

  • Ideally, the NCL script is small and illustrates the problem.

    Some people send us scripts that contain large numbers of lines commented out. This makes it difficult for us to follow. Please clean up the code prior to sending scripts.

  • Since image files (e.g. PS files) can be large, please convert to (say) PNG or GIF. If possible, make the images available via the web.

Using ftp to upload data and/or scripts

Follow these instructions for ftp-ing files if you need have large datasets and/or other files you need to provide to the NCL team.

After you've uploaded the files, send email to ncl-talk (you must subscribe first) with the following information:

  • The exact names of the file(s) and their approximate size(s).
  • The version of NCL you are running (ncl -V).
  • The type of system you are on (uname -a).
  • The exact error message you are getting. If there is no error message, then a detailed description of the problem.

Thank you for your consideration.