Thanks for the hint. I tried the syntax but I am getting error:
script:
# reading data
triplengthfile <- as.data.frame ( read.spss ( file = "triplengthfile.sav" )
)
#Defining projection
coordinates ( triplengthfile ) <- cbind ( triplengthfile $ longa,
triplengthfile $ lata )
coords <- cbind ( triplengthfile $ longa, triplengthfile $ lata )
proj4string ( triplengthfile ) <- CRS ( "+proj=longlat +ellps=WGS84" )

#projecting to Albers conical
triplengthfile <- spTransform ( triplengthfile , CRS =
CRS ( "+proj=aea +lat_1=24 +lat_2=31.5 +lat_0=24 +lon_0=-84 +x_0=400000
+y_0=0 +ellps=GRS80 +units=m +no_defs" ) )

#updating coords
coords <- coordinates( triplengthfile )
IDs <- rownames ( triplengthfile@data )

#defining neighbors for Household members
HHneighbor.knn <- mapply ( function (n,coord) knearneigh ( x=coord, k=n,
longlat=FALSE, RANN=TRUE), HHNUM, lapply (1:nrow(coords),function(i)
coords[i,]  ))

which HHNUM is the number of HH members in matrix class (is defined for
each observation(individual))

But I am getting error:
Error:

Error in knearneigh(x = coord, k = n, longlat = FALSE, RANN = TRUE) :
  Data not in matrix form

Appreciate you could help me solve this error.
appreciate your help.
Roosbeh Nowrouzian
PhD student
Department of Civil Engineering
University of Florida

On Wed, Mar 28, 2012 at 10:35 PM, Tom Gottfried <tom.gottfried@tum.de>wrote:

> Hi,
>
> Am 29.03.2012 01:08, schrieb Roosbeh Nowrouzian:
>
>  Hi list members:
>>
>> Is there any way to define neighbors in R as any other observation
>> with distance to the corresponding point equal to 0.
>>
>> I am trying to define neighbors base on the same location ( the same
>> Household members are linked to each other). I tried defining
>>
>> weights base on  fixed distance bounds:
>> neighbordistance.nb<- dnearneigh ( coords, d1=0, d2=0.00001, row.names=IDs
>> )
>> But this function does not define other Household members (distance=0) as
>> the neighbor.
>>
>> When trying fixed number of neighbors:
>> neighbor3.knn<- knearneigh ( x=coords , k=3, longlat= FALSE, RANN=TRUE )
>> This function defines other Household members(distance =0) as neighbor but
>> the problem with this function is that each Household has different
>> Household number so different number of neighbors is required for each
>> Household.
>>
>
> neighbor3.knn <-
>   mapply(function(n, coord) knearneigh(x=coord,
>                                        k=n, longlat=FALSE,RANN=TRUE),
>          ns, lapply(1:nrow(coords), function(i) coords[i,]))
>
> Assuming you have a vector 'ns' with the number of household members per
> household, this should give you a list with each element defining the
> neighbours you desire. I hope I didn't misunderstand your question.
>
> HTH,
> Tom
>
>  It would be kind of you letting me know if there is a way to define
>> neighbors base on  zero distance with the corresponding point.
>> Appreciate it.
>>
>> Roosbeh Nowrouzian
>> PhD student
>> Department of Civil Engineering
>> University of Florida
>>
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>>
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