Min function returns Min[2.05875,] instead of just 2.05875

Discussion in 'Mathematica' started by dg, Jun 1, 2009.

  1. dg

    dg Guest

    I have an matrix "data" with 17x248 real numbers.

    When I enter Min[data], I get
    Min[2.05875, ] as a result, instead of just the number 2.05875.

    This is Mathematica 7.0.1 on Mac OS X.

    Why?

    How can I get just the number from the result?

    TIA
     
    dg, Jun 1, 2009
    #1
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  2. dg

    dr DanW Guest

    This is just a guess, but you may have an invisible character as an
    element in your matrix that is being interpreted as a symbol. The
    second argument of the Min is in your matrix somewhere. Do a FullForm
    on the output to see what the second argument to Min is, then
    eliminate it from your matrix.
     
    dr DanW, Jun 2, 2009
    #2
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  3. This is precisely the result you get if one of the matrix entries
    contains an empty string (""). I'd check my data for this if I were
    you.

    Cheers -- Sjoerd
     
    Sjoerd C. de Vries, Jun 2, 2009
    #3
  4. dg

    Francesco Guest

    Non numerical entry after the comma.
    -Francesco
     
    Francesco, Jun 2, 2009
    #4
  5. Hi,

    can you explain what the minimum of a set of
    vectors with dimension 248 is ?

    Or do you mean Min[Flatten[data]] ?

    Regards
    Jens
     
    Jens-Peer Kuska, Jun 2, 2009
    #5
  6. dg

    Szabolcs Guest

    You typed Min[data,] instead of Min[data].
    Remove the comma.
     
    Szabolcs, Jun 2, 2009
    #6
  7. I think you have a non-printing character in your matrix.
    Min[2,3,4,5,x] reduces to Min[2,x]. But if the "x" was something so
    strange that Mathematica did not have a way of printing it, then I think
    we would see Min[2,].

    If "data" is stored as a list of 17 row, each of which should contain
    248 numbers, then look for a row with Length[row] = 249.
     
    Christopher Henrich, Jun 2, 2009
    #7
  8. dg

    pfalloon Guest

    Hi,
    It's hard to see exactly what's going wrong because you have not
    included the exact code, but at a guess I'd say there may some
    invisible wrapper around the list of numbers, which is preventing Min
    evaluating properly.

    In general, the behaviour should be as follows:

    In[290]:= data = RandomReal[10, {17, 248}];

    Min[data]
    Out[291]= 0.00017248

    Cheers,
    Peter.
     
    pfalloon, Jun 2, 2009
    #8
  9. dg

    dg Guest

    Solution: The matrix had missing values.

    This will work in such cases:
    Min[Cases[data // Flatten, _?NumericQ]]

    Thanks to a helpful person that found this solution.
     
    dg, Jun 2, 2009
    #9
  10. Min flattens lists!

    --
    Murray Eisenberg
    Mathematics & Statistics Dept.
    Lederle Graduate Research Tower phone 413 549-1020 (H)
    University of Massachusetts 413 545-2859 (W)
    710 North Pleasant Street fax 413 545-1801
    Amherst, MA 01003-9305
     
    Murray Eisenberg, Jun 3, 2009
    #10
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