Why not use the thematic mapping ? If you choose the "classes of values
type" with the "same number of records methods", it will rank your data
and split them in equal number of classes : the legend will give you the
limits of the classes.. if you want 25% make it 4 classes, 20% make it 5
classes, 10% make 10 classes.. but if you have 960 combinations, then
that will make 960 layers.. I'm not sure whether MIP would support that
many layers however.
Alternatively, export a table from MapInfo, with the paddocks in the lines
and your combinations of varieties and soil in the columns. Then use a
statistical program in order to compute the percentiles or quartiles.. If
you don't have SAS or SPSS, or another statistical package, EXCEL has
these functions.. : CENTILE(matrix;k) send back the kth centile : if you
choose CENTILE (c2:c115000; 10) would return you the limit between the
upper 10 percent of production volume and the rest..
Christiane
Vient de para�tre : Lausanne � la carte, le nouvel atlas lausannois
Christiane Roh - Section Statistique Lausanne
Statistique Lausanne - SCRIS
Service cantonal de recherche et d'information statistiques
Rue de la Paix 6, CH-1014 Lausanne
t�l.: +41(021) 316 29 51
fax : +41(021) 316 29 50
"Robert Crossley" <[EMAIL PROTECTED]>
08.03.2005 04:02
Pour : [EMAIL PROTECTED]
cc : "MapInfo List" <[email protected]>
Objet : Re: MI-L top 25% query
Hi martin
I have 115,000 odd results with about 960 total combinations of variety
and soil. Thats a lot of selections. Would prefer to do it more directly
if there is a way.
r
On Tue, 8 Mar 2005 13:29:33 +1100, Martin Higham <[EMAIL PROTECTED]>
wrote:
> Hi Robert,
>
> For each class (ie. combination of soil and variety) you need to order
> the
> production values, then select the 75th percentile value - ie. for
> ascending
> sort, get the production value for RowID = Total Rows*3/4.
>
> This is of course trivial - the complication comes in that you need to
> create a separate sorted selection for each class. Easy to do manually,
> but
> if you've got a lot of classes, could be prone to error.
>
>
> Best Regards,
>
> Martin Higham
> Avantra Geosystems
>
> ph (61 3) 8504 0428 0425-730-428
> fx (61 3) 9596 7997
> www.avantra.com.au
>
>
>
>
>> -----Original Message-----
>> From: Robert Crossley [mailto:[EMAIL PROTECTED]
>> Sent: Tuesday, 8 March 2005 13:26
>> To: MapInfo List
>> Subject: MI-L top 25% query
>>
>>
>>
>> Hi,
>>
>> I have a table of data that gives me the amount of product produced for
>> paddocks, and each paddock has a soil and variety attribute. I
>> am trying
>> to work out how to get a query that will give me the production
>> level that
>> is equivalent the top 25% (or 10%) of paddocks produced for each
>> combination of soil and variety.
>>
>> I suspect that I could do this with some statistical functions,
>> but am not
>> sure - been about 20 years since I did stats - and can't find
>> reference to
>> a std dev function in the manual, but perhaps there is a better way.
>>
>> Any suggestions - and it is being done in Mapbasic.
>>
>> Thanks
>> r
>>
>>
>> --
>> ________________________________________________
>>
>> Robert Crossley
>>
>> Agtrix P/L
>> 9 Short St
>> PO Box 63
>> New Brighton 2483
>> Far Southern Queensland
>> AUSTRALIA
>>
>> 153.549004 E 28.517344 S
>>
>> P: 02 6680 1309
>> F: 02 6680 5214
>> M: 0419 718 642
>> E: [EMAIL PROTECTED]
>> W: www.agtrix.com
>> W: www.wotzhere.com
>> skype: robertcrossley
>>
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>
--
________________________________________________
Robert Crossley
Agtrix P/L
9 Short St
PO Box 63
New Brighton 2483
Far Southern Queensland
AUSTRALIA
153.549004 E 28.517344 S
P: 02 6680 1309
F: 02 6680 5214
M: 0419 718 642
E: [EMAIL PROTECTED]
W: www.agtrix.com
W: www.wotzhere.com
skype: robertcrossley
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