Re: union table
- To: mathgroup at smc.vnet.net
- Subject: [mg108157] Re: union table
- From: Nicola Mingotti <n-no-mingotti at g-spam-mail.com>
- Date: Tue, 9 Mar 2010 06:25:03 -0500 (EST)
- References: <hn2mg7$47r$1@smc.vnet.net>
On 2010-03-08 12:19:35 +0100, maria giovanna dainotti said:
> Dear Mathgroup,
> I need to join two table in which one column should be the same. And if=
> it is not the same at the same position I would like to find the way
> that Math can match the column when for example the tenth column of the=
> first table should be the same of the forth column of the second table.
>
> AI could do also with a do operation but the lenght of the table can be=
> also different.
>
> Is there a more general method to figure out this problem?
> for example with union Union[{DataFitend},{DataFitLx}]
> it returns all the table instead I would like to eliminate one column
> that it is the same.
> how can i do?
> Thanks a lot
> Maria
Hello,
I don't know if i understood well but the problem could be that what
you consider two "equal" list are not precisely the same.
1) In this case it works as expected
a = {{1, 2, 3}, {4, 5, 6}};
b = {{1, 2, 3}, {7, 8, 9}};
In[40]:= Union[a, b]
Out[40]= {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}
2) in this case don't :
a = {{1.0, 2, 3}, {4, 5, 6}};
b = {{1, 2, 3}, {7, 8, 9}};
Union[a, b]
=> {{1, 2, 3}, {1., 2, 3}, {4, 5, 6}, {7, 8, 9}}
.... because 1 can be considered equal to 1.0 but even not, it depends on
how you define equality.
bye
nicola