Thank you very much for your help!

On Wed, Jan 16, 2013 at 1:05 PM, Jacob van Etten <[email protected]>wrote:

> Hi Josephine,
>
> The main error seems to occur in the raster package. The raster with
> logical values becomes numeric when a single value is changed using [].
>
> a <- raster(ncol=10, nrow=10)
> a[] <- FALSE
> a[50] <- TRUE
> class(values(a))
>
> In the code below I use a work-around that solves your problem for now
> (and changes some other minor issues in your code).
>
> map.test <- raster(ncol=10,nrow=10)
> map.test[] <- 100
>
> origin <- raster(map.test)
> vals <- rep(FALSE, times=100)
> vals[93] <- TRUE
> origin[] <- vals
>
> goal <- raster(map.test)
> vals <- rep(FALSE, times=100)
> vals[9] <- TRUE
> goal[] <- vals
>
> tran.test <- transition(map.test, transitionFunction=mean, directions=8)
>
> passage(tran.test, origin, goal, theta=0.00001, totalNet="total")
>
> Best,
>
> Jacob.
>
>   ------------------------------
> *From:* Josephine Walker <[email protected]>
> *To:* [email protected]
> *Sent:* Wednesday, 16 January 2013, 7:21
> *Subject:* [R-sig-Geo] RasterLayer for origin and goal in passage
> function (gdistance)
>
> Hello everyone,
>
> I'm new to this list and to using R for geographical data analysis. I am
> playing around with the gdistance package but have a small problem:
>
> I am trying to use a RasterLayer to define origin and goal points for the
> passage function, which I believe is possible based on the documentation:
>
> origin
> SpatialPoints, matrix or numeric object with coordinates or RasterLayer
> object with origin cells set to TRUE
>
> goal
> SpatialPoints, matrix or numeric object with coordinates or RasterLayer
> object with origin cells set to TRUE
>
> Here is a basic idea of what I'm doing:
>
> ####################################
> map.test <- raster(ncol=10,nrow=10)
> map.test[] <- 100
>
> origin <- raster(ncol=ncol(map.test),nrow=nrow(map.test))
> origin[] <- FALSE
> origin[93] <- TRUE
> goal <- raster(ncol=ncol(map.test),nrow=nrow(map.test))
> goal[] <- FALSE
> goal[9] <- TRUE
>
> tran.test <- transition(map.test,transitionFunction=mean,directions=8)
>
> passage(tran.test, origin, goal,theta=0,totalNet=total)
>
> and this gives the error message:
> Error in which(getValues(origin)) : argument to 'which' is not logical
> ##################################
>
> Any ideas what I'm doing wrong?
>
> Thanks very much
> Josephine
>
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>
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