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Combining results

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It is possible to combine the results from different searches to produce a new result. The searches have to be from the same library. The possible modes of combination are "AND", "OR" and "BUTNOT".

AND
eg human AND trypsin will give results containing both human and trypsin
EMBL:	 (TRYPSIN [Keyword] AND HUMAN [Organism])	 5
OR
eg human OR trypsin will give all the results containing human and all the results containing trypsin
EMBL:	 (TRYPSIN [Keyword] OR HUMAN [Organism])	 423587
BUTNOT
eg human BUTNOT trypsin will give all results containing human except those also containing trypsin. As can be seen in the example below, the more useful order "trypsin BUTNOT human", gives a very different result.
EMBL:	 (HUMAN [Organism] BUTNOT TRYPSIN [Keyword])	 423538
EMBL:	 (TRYPSIN [Keyword] BUTNOT HUMAN [Organism])	 44

The format of the results depends on the type of indices used. The above examples are for embl indices. If srs5.1 indices are used, the results would look like:

Q0: [embl-Keywords: trypsin] 51

Q1: [embl-Organism: human] 680320

Q2: Q0 & Q1 7

Q3: Q0 | Q1 680364

Q4: Q0 ! Q1 44

where: Q2 is Q0 AND Q1

Q3 is Q0 OR Q1

Q4 is Q0 BUTNOT Q1

For example, to search for human trypsin in the EMBL library:

  1. Set library = EMBL, field = Organism, text = "human", mode = word, press "Search"
  2. Set library = EMBL, field = Keyword, text = "trypsin", mode = word, press "Search" This will produce results such as:
    Q0: [embl-Organism: human]  680320
    Q1: [embl-Keywords: trypsin]  51
    
  3. Select the human result with the left mouse button and use the right mouse button to invoke the popup menu. Select "Combine result" then "AND".
  4. Select the trypsin result with the left mouse button.

A new result will be added to the end of the result list:

Q2: Q0 & Q1 7

Alternatively it is possible to select results to be combined by selecting multiple results and then selecting the combination mode. Note that in this case the order of evaluation is the same as the order the items in the list from top to bottom. As seen above, the order of evaluation of the BUTNOT operator is very important.

It is possible to build up more complicated searches by using the result of one combination with another search.


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This page is maintained by James Bonfield. Last generated on 2 Febuary 1999.
URL: http://www.mrc-lmb.cam.ac.uk/pubseq/manual/seqlib_6.html