Possible bug in v9.0 Rest[] function

Question

Just to be clear, this all works perfectly in v8.0.4.0. It only fails me in v9.0. I use 64-bit Linux, 64-bit versions of Mathematica, and I have 16GB of RAM.

I have a data file formatted as follows:

Date,Open,High,Low,Close,Volume,OpenInt
19700102,1.6047,1.6140,1.6047,1.6140,881445,0
19700105,1.6140,1.6235,1.6047,1.6235,549208,0
19700106,1.6140,1.6140,1.6047,1.6140,508527,0
19700107,1.6140,1.6424,1.6140,1.6424,752620,0

There are 10839 rows of data in the file. I store the first col of data in a list called "dataDate", the second col of data in "dataOpen", etc... All works great until I try to print the data back to the screen. Version 8 displays the data as expected; but version 9 borks, the kernel resets, and all function definitions and data structures are reset.

Here's the updated, simple code:

data = Import["pg.us.txt", "Data"];

(* Read the first row of data, to get the column headings *)
dataColumnHeadings = data[[1, All]]

(* Store each column of data in a separate list, removing the first element with Rest[] *)
dataDate = Rest[data[[All, 1]]];
dataOpen = Rest[data[[All, 2]]];
dataHigh = Rest[data[[All, 3]]];
dataLow = Rest[data[[All, 4]]];
dataClose = Rest[data[[All, 5]]];
dataVolume = Rest[data[[All, 6]]];
dataOpenInt = Rest[data[[All, 7]]];
Length[dataDate]
Length[dataOpen]
Length[dataHigh]
Length[dataLow]
Length[dataClose]
Length[dataVolume]
Length[dataOpenInt]

Now, if I try to display the contents of any of the seven lists, (by simply typing the list's name and evaluating it), it works perfectly in version 8. But in version 9, any attempt to evaluate a list by evaluation of its name causes Mathematica 9 to bork: all imported data is lost as all variables are undefined, user-defined functions cleared, etc. (blue text instead of black text). It takes about 6-7 seconds for the error to occur, after you evaluate the list name and it displays the truncated output.

Here are links to my updated test notebook and data file if anyone would be kind enough to see if this is just a problem with my machine, or a bug:

https://dl.dropbox.com/u/1224415/test_case.nb

https://dl.dropbox.com/u/1224415/pg.us.txt

Thanks

UPDATE: As I stated in a response below, removing the "Rest[]" function, used to remove the first element of each list, seems to fix the problem. Perhaps I'll try to remove the first element in some other manner; or perhaps try to use "Rest[]" in a three step process (wasting RAM):

dataDate = data[[All, 1]];
dataDate2 = Rest[dataDate];
Clear[dataDate];

UPDATE 2: It doesn't matter how much I mess with the list data: as soon as I use the "Rest[]" command on it, and display the results to screen, the program borks. I'm calling this a bug and contacting Wolfram. This is what I get for being an early adopter...

Answer 1

It works fine for me both on a (more or less) pristine 64-bit Ubuntu 12.10 machine and on OS X, so I guess it's an issue on your machine. Try launching with mathematica -cleanStart and see if that fixes it. If not, I suggest you contact Technical Support for additional assisstance.

Update: As I note in the comments below, if the kernel crashes after an output is printed, it is possible this might be due to a bug in the Suggestions Bar. You can try turning of the Suggestions Bar in Edit > Preferences (or Mathematica > Preferences on OS X) and see if this helps. Obviously a crash in the Suggestions Bar is a bug which should be fixed.

In this particular case, you should find that only dataDate produces a crash. I have traced this crash to the fact there is a long sequence of exact integers, so number-theoretic functions are called make predictions. One of them crashes the kernel--I have sent this off to the relevant developer. In the mean time, here are some possible workarounds:

1) Replace the integers with date-lists. You can still compute with these, and will probably get better predictions out of this. Plus you'll be able to format them using DateString and compute using other date-related functions.

dataDate = {Quotient[#, 10000], Mod[Quotient[#, 100], 100],  Mod[#, 100]} &  /@ dataDate

2) Use N or ToString to make your dates not be integers. This may be easier/more useful depending on how exactly you use these dates, and will avoid your particular crash.

dataDate = dataDate // N
dataDate = ToString /@ dataDate

Answer 2

Disabling the "Suggestions Bar" notebook interface enhancement, located in Edit -> Preferences, fixes this issue in both of my test cases: 64-bit Linux and 64-bit Windows 7. This feature is new in v9.0. I will continue to follow up with Wolfram to see if this is a bug.

Answer 3

Just out of curiosity, and following up on Szabolcs' comment, what do you see if you remove the semi-colons (as I did) in the following lines of your code?:

$Version
data = Import["Rest.txt", "Data"]
dataColumnHeadings = data[[1, All]]
dataDate = Rest[data[[All, 1]]]

You should see something like the following (with the corresponding information for your operating system):