[AstroPy] ValueError in vstacking tables

[Aldcroft, Thomas]

Hi Brian,

Below is what I think is a minimal example of what you are describing.  Can
you look at this and first reproduce that this works for you, and second,
can you guess what might be different in your full example vs. my minimal
example?

In [19]: t1 = Table([[1], [2]], names=['a', 'b'])

In [20]: t2 = Table([[3], [4]], names=['b', 'c'])

In [23]: t12 = vstack([t1, t2], join_type='outer')

In [24]: t12
Out[24]:
<Table masked=True length=2>
  a     b     c
int64 int64 int64
----- ----- -----
    1     2    --
   --     3     4

In [25]: t12[0]
Out[25]:
<Row 0 of table
 values=(1, 2, --)
 dtype=[('a', '<i8'), ('b', '<i8'), ('c', '<i8')]>


On Wed, Jun 17, 2015 at 2:08 PM, Brian Cherinka <cherinka at di.utoronto.ca>
wrote:

> Hi,
>
> I’m trying to vstack (vertically stack) two Astropy tables with different
> numbers of columns.  The tables appear to stack correctly without error.
> However, upon attempting to index a row in the table, it throws me this
> error
>
> <repr(<astropy.table.row.Row at 0x10c72ed50>) failed: ValueError: setting
> an array element with a sequence.>
>
> I’m not trying to do anything fancy with mixed columns, or Quantities.
> Just stackin’ two good ol’ natural Tables together.     One table has 84
> columns, and another has 57, which are all a part of the 84 in the first
> table.  At first glance I would guess it’s a mismatch in the dtypes of a
> particular column that I’m trying to merge.  However, the columns all have
> the same dtype, format, and they are in the same order.  I get no messages
> regarding any kind of merge errors.
>
> Any ideas on this?
>
> Thanks, Brian
>
> P.S. Full print of traceback below
>
> table3 = vstack([table1, table3],join_type=‘outer’)
> print table3[0]
> ---------------------------------------------------------------------------
> ValueError                                Traceback (most recent call last)
> <ipython-input-278-a0c75e8d3ef3> in <module>()
> ----> 1 print tmp3[0]
>
> /Users/Brian/anaconda/lib/python2.7/site-packages/astropy/table/row.pyc in
> __repr__(self)
>     176     def __repr__(self):
>     177         return "<{3} {0} of table\n values={1!r}\n
> dtype={2}>".format(
> --> 178             self.index, self.as_void(), self.dtype,
> self.__class__.__name__)
>     179
>     180
>
> /Users/Brian/anaconda/lib/python2.7/site-packages/numpy/ma/core.pyc in
> __repr__(self)
>    5699             return self._data.__repr__()
>    5700         m = tuple(m)
> -> 5701         if not any(m):
>    5702             return self._data.__repr__()
>    5703         p = masked_print_option
>
> /Users/Brian/anaconda/lib/python2.7/site-packages/numpy/ma/core.pyc in
> __call__(self, a, *args, **params)
>    6089         method = getattr(MaskedArray, method_name, None)
>    6090         if method is not None:
> -> 6091             return method(MaskedArray(a), *args, **params)
>    6092         # Still here ? OK, let's call the corresponding np function
>    6093         method = getattr(np, method_name)
>
> /Users/Brian/anaconda/lib/python2.7/site-packages/numpy/ma/core.pyc in
> __new__(cls, data, mask, dtype, copy, subok, ndmin, fill_value, keep_mask,
> hard_mask, shrink, **options)
>    2649         """
>    2650         # Process data............
> -> 2651         _data = np.array(data, dtype=dtype, copy=copy, subok=True,
> ndmin=ndmin)
>    2652         _baseclass = getattr(data, '_baseclass', type(_data))
>    2653         # Check that we're not erasing the mask..........
>
> ValueError: setting an array element with a sequence.
>
>
>
>
> ---------------------------------------
> Brian Cherinka, Ph.D
> Dunlap Institute for Astronomy & Astrophysics
> University of Toronto
> Toronto, ON, Canada M5S 3H4
> phone: 416-978-7299
> email: cherinka at di.utoronto.ca
> ----------------------------------------
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
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