[R] Identyfing rows with specific conditions

[Bert Gunter]

You haven't said whether your "table" is a matrix or data frame.
Presumably the latter.

Nor have you answered my question about whether order of your meal
code pairs matters.

Another question: can meals be replicated for an ID or are they all different?

Finally, is this a homework assignment or class project of some sort?
Or is it a real task -- i.e., what is the context?

Again, be sure to cc the list.

-- Bert
Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Mon, May 22, 2017 at 1:56 AM, Allaisone 1 <allaisone1 at hotmail.com> wrote:
> Hi Bert ..,
>
>
> The number of meals differ from one customer to other customer. You may find
> one customer with only one meal and another one with 2,3 or even rarely 30
> meals. You may also
>
> find no meal at all for some customers so the entire row takes the missing
> value "\N" . Any
>
> row starts with the meals codes first, then all missing values are to the
> right end of the table.
>
> ________________________________
> From: Bert Gunter <bgunter.4567 at gmail.com>
> Sent: 22 May 2017 03:11:11
> To: Allaisone 1
> Cc: r-help at r-project.org
> Subject: Re: [R] Identyfing rows with specific conditions
>
> Clarification:
>
> Does each customer have the same number of meals or do they differ
> from customer to customer? If the latter, how are missing meals
> notated? Do they always occur at the (right) end or can they occur
> anywhere in the row?
>
> Presumably each customer ID can have many different meal code
> combinations, right ?(since they can have 30 different meals with
> potentially 30 choose 2 = 435 combinations apiece)
>
> Please make sure you reply to the list, not just to me, as I may not
> pursue this further but am just trying to clarify for anyone else who
> may wish to help.
>
>
> Cheers,
> Bert
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along
> and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
>
> On Sun, May 21, 2017 at 5:10 PM, Allaisone 1 <allaisone1 at hotmail.com> wrote:
>>
>> Hi All..,
>>
>> I have 2 tables. The first one contains 2 columns with the headers say
>> "meal A code" & "meal B code " in a table called "Meals" with 2000 rows each
>> of which with a different combination of meals(unique combination per row).
>>
>>
>>>Meals
>>
>>     meal A code      meal B code
>>
>> 1          34                   66
>>
>> 2           89                  39
>>
>> 3           25                   77
>>
>> The second table(customers) shows customers ids in the first column with
>> Meals codes(M) next to each customer. There are about 300,000 customers
>> (300,000 rows).
>>
>>> Customers
>>      1         2     3       4    ..30
>>      id       M1  M2   M3
>> 1   15      77    34    25
>> 2   11      25    34     39
>> 3    85     89     25    77
>> .
>> .
>> 300,000
>>
>> I would like to identify all customers ids who have had each meal
>> combination in the first table so the final output would be the first table
>> with ids attached next to each meal combination in each row like this:
>>
>>>IdsMeals
>>
>>
>>   MAcode  MBcode  ids
>>
>> 1     34        39            11
>>
>> 2     25       34              15   11
>>
>> 3      25     77                15   85
>>
>> Would you please suggest any solutions to this problem?
>>
>> Regards
>>
>>         [[alternative HTML version deleted]]
>>
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