[R-sig-Geo] R-sig-Geo Digest, Vol 126, Issue 22
Hj Sidup Hj Sirabaha
sidup.sirabaha at gmail.com
Sun Mar 2 02:50:54 CET 2014
ry
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> On 25 Feb, 2014, at 7:00 pm, r-sig-geo-request at r-project.org wrote:
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> Today's Topics:
>
> 1. ifelse with multiple rasters (Laura Poggio)
> 2. Fwd: ifelse with multiple rasters (Laura Poggio)
> 3. Re: Fwd: ifelse with multiple rasters (Jonathan Greenberg)
> 4. How to do an anamorphosis on R? (Gilles Benjamin Leduc)
> 5. Re: Fwd: ifelse with multiple rasters (Laura Poggio)
> 6. Extract time series value for a given coodinate from an
> unusual NetCDF file (ping yang)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 24 Feb 2014 14:15:22 +0000
> From: Laura Poggio <laura.poggio at gmail.com>
> To: R geo forum <r-sig-geo at stat.math.ethz.ch>
> Subject: [R-sig-Geo] ifelse with multiple rasters
> Message-ID:
> <CAKmfgFPL1PKzx0DGBYRGQXM5gGhzbAzB8fDceYoT8vW6JmeFLA at mail.gmail.com>
> Content-Type: text/plain
>
> Dear list,
> I am struggling to find a way to do a simple if statement with multiple
> rasters in raster.
>
> For example:
> ifelse(rst_a==0 & rst_B=1,2,0)
>
> Which is the simplest and most efficient way to implement it? especially
> when considering large (>10,000,000 cells) rasters?
>
> Thank you in advance
>
> Laura
>
> [[alternative HTML version deleted]]
>
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 24 Feb 2014 14:16:33 +0000
> From: Laura Poggio <laura.poggio at gmail.com>
> To: r-sig-geo at r-project.org
> Subject: [R-sig-Geo] Fwd: ifelse with multiple rasters
> Message-ID:
> <CAKmfgFNOZpi0QR4KPrCddAf9O12rYKv0EAeSu5Rom7qVfPWRSA at mail.gmail.com>
> Content-Type: text/plain
>
> Dear list,
> I am struggling to find a way to do a simple if statement with multiple
> rasters in raster.
>
> For example:
> ifelse(rst_a==0 & rst_B=1,2,0)
>
> Which is the simplest and most efficient way to implement it? especially
> when considering large (>10,000,000 cells) rasters?
>
> Thank you in advance
>
> Laura
>
> [[alternative HTML version deleted]]
>
>
>
> ------------------------------
>
> Message: 3
> Date: Mon, 24 Feb 2014 08:50:06 -0600
> From: Jonathan Greenberg <jgrn at illinois.edu>
> To: Laura Poggio <laura.poggio at gmail.com>
> Cc: "r-sig-geo at r-project.org" <r-sig-geo at r-project.org>
> Subject: Re: [R-sig-Geo] Fwd: ifelse with multiple rasters
> Message-ID:
> <CABG0rfuEW28tOCMm841mAjVgZaZHkTBBJdSn9Lein1i75byrXw at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Laura:
>
> If this is a straight masking procedure, you can do some
> multiplication tricks in raster like:
>
> output = rst_a*rst_B*2
>
> or look at
> ?overlay
>
> or take a look at
> ?mask
>
> I suspect mask and overlay are faster than the raster algebra
> statement (Robert, is this correct?)
>
> If you want to use rasterEngine for parallel processing, you can do
> something like this:
>
> library(spatial.tools)
>
> # Set X to the number of CPUs you want top use and uncomment this for
> parallel processing:
> # sfQuickInit(cpus=X)
>
> rst_test <- function(rst_a,rst_B)
> {
> return(ifelse(rst_a==0 & rst_B==1,2,0))
> }
>
> # Fill in the rasters you intend to use here:
> raster_check <-
> rasterEngine(rst_a=someraster,rst_B=someotherraster,fun=rst_test)
>
> # Uncomment to stop the parallel engine if need be:
> # sfQuickStop()
>
> --j
>
>> On Mon, Feb 24, 2014 at 8:16 AM, Laura Poggio <laura.poggio at gmail.com> wrote:
>> Dear list,
>> I am struggling to find a way to do a simple if statement with multiple
>> rasters in raster.
>>
>> For example:
>> ifelse(rst_a==0 & rst_B=1,2,0)
>>
>> Which is the simplest and most efficient way to implement it? especially
>> when considering large (>10,000,000 cells) rasters?
>>
>> Thank you in advance
>>
>> Laura
>>
>> [[alternative HTML version deleted]]
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo at r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
>
>
> --
> Jonathan A. Greenberg, PhD
> Assistant Professor
> Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
> Department of Geography and Geographic Information Science
> University of Illinois at Urbana-Champaign
> 259 Computing Applications Building, MC-150
> 605 East Springfield Avenue
> Champaign, IL 61820-6371
> Phone: 217-300-1924
> http://www.geog.illinois.edu/~jgrn/
> AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307, Skype: jgrn3007
>
>
>
> ------------------------------
>
> Message: 4
> Date: Mon, 24 Feb 2014 15:24:35 +0000
> From: "Gilles Benjamin Leduc" <gbl1 at hi.is>
> To: R-sig-Geo at r-project.org
> Subject: [R-sig-Geo] How to do an anamorphosis on R?
> Message-ID: <3011-530b6400-7f-7f728600 at 71854736>
> Content-Type: text/plain; charset="utf-8"
>
> Hi all,
>
> I would like to make an anamorphosis map, id est, a map where some other distance measurement are used instead geographical distance. In my case I would like to plot an anamorphosis of Iceland using genetical distence insteand of geographical distence.
> I have got .shp maps and equivalents.
> How to make such a distortion?
> Best regards
> Benjamin
>
>
>
> ------------------------------
>
> Message: 5
> Date: Mon, 24 Feb 2014 15:50:10 +0000
> From: Laura Poggio <laura.poggio at gmail.com>
> To: Jonathan Greenberg <jgrn at illinois.edu>
> Cc: "r-sig-geo at r-project.org" <r-sig-geo at r-project.org>
> Subject: Re: [R-sig-Geo] Fwd: ifelse with multiple rasters
> Message-ID:
> <CAKmfgFPBUrzqa9PS26R62YEP8EtNWUqz9fuaXjYwR-eQZWzZXQ at mail.gmail.com>
> Content-Type: text/plain
>
> Dear Jonathan,
> thank you very much. I will have a closer look to overlay, but I think that
> your example with Spatial.tools is the most straightforward for the way I
> think... and it can be used with multiple processors.
>
> Thanks
>
> Laura
>
>
>> On 24 February 2014 14:50, Jonathan Greenberg <jgrn at illinois.edu> wrote:
>>
>> Laura:
>>
>> If this is a straight masking procedure, you can do some
>> multiplication tricks in raster like:
>>
>> output = rst_a*rst_B*2
>>
>> or look at
>> ?overlay
>>
>> or take a look at
>> ?mask
>>
>> I suspect mask and overlay are faster than the raster algebra
>> statement (Robert, is this correct?)
>>
>> If you want to use rasterEngine for parallel processing, you can do
>> something like this:
>>
>> library(spatial.tools)
>>
>> # Set X to the number of CPUs you want top use and uncomment this for
>> parallel processing:
>> # sfQuickInit(cpus=X)
>>
>> rst_test <- function(rst_a,rst_B)
>> {
>> return(ifelse(rst_a==0 & rst_B==1,2,0))
>> }
>>
>> # Fill in the rasters you intend to use here:
>> raster_check <-
>> rasterEngine(rst_a=someraster,rst_B=someotherraster,fun=rst_test)
>>
>> # Uncomment to stop the parallel engine if need be:
>> # sfQuickStop()
>>
>> --j
>>
>> On Mon, Feb 24, 2014 at 8:16 AM, Laura Poggio <laura.poggio at gmail.com>
>> wrote:
>>> Dear list,
>>> I am struggling to find a way to do a simple if statement with multiple
>>> rasters in raster.
>>>
>>> For example:
>>> ifelse(rst_a==0 & rst_B=1,2,0)
>>>
>>> Which is the simplest and most efficient way to implement it? especially
>>> when considering large (>10,000,000 cells) rasters?
>>>
>>> Thank you in advance
>>>
>>> Laura
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo at r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>>
>>
>> --
>> Jonathan A. Greenberg, PhD
>> Assistant Professor
>> Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
>> Department of Geography and Geographic Information Science
>> University of Illinois at Urbana-Champaign
>> 259 Computing Applications Building, MC-150
>> 605 East Springfield Avenue
>> Champaign, IL 61820-6371
>> Phone: 217-300-1924
>> http://www.geog.illinois.edu/~jgrn/
>> AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307, Skype: jgrn3007
>
> [[alternative HTML version deleted]]
>
>
>
> ------------------------------
>
> Message: 6
> Date: Mon, 24 Feb 2014 21:27:55 -0600
> From: ping yang <pingyang.whu at gmail.com>
> To: r-sig-geo <r-sig-geo at r-project.org>
> Subject: [R-sig-Geo] Extract time series value for a given coodinate
> from an unusual NetCDF file
> Message-ID:
> <CAK8gSG9+gqx6W=496oHysYnm9qiPdkAkt5UcGwL6opxsDY18QA at mail.gmail.com>
> Content-Type: text/plain
>
> Hi r-sig-geo,
>
> previously I used following code to extract time series value for a given
> coodinate from a netcdf file:
> require(raster)
> require(ncdf)
> require(sp)
> X1 <- -90.5167
> Y1 <- 33.45
> MS <- cbind(X1,Y1)
> p <- SpatialPoints(MS)
> year <- 1981
> setwd("e:/PRISM/NetCDF/")
> filename <- paste("PRISM_MS")
> pptfile <- paste("ppt","_",year,".nc",sep='')
> b_ppt <- brick(pptfile,varname='ppt')
> ppt <- extract(b_ppt,coordinates(p))
>
> it was successful. However, when I use the same method for another NetCDF
> (which has unusual dimension), i got errors, then I check the difference,
> it showed that the dimension for the two files are different:
> The file is working has following information:
> Netcdf file 1:
> class : RasterBrick
> *dimensions : 621, 1405, 872505, 365 (nrow, ncol, ncell, nlayers)*
> resolution : 0.04166667, 0.04166667 (x, y)
> extent : -125.0208, -66.47917, 24.0625, 49.9375 (xmin, xmax, ymin,
> ymax)
> coord. ref. : +proj=longlat +datum=NAD83 +no_defs +ellps=GRS80
> +towgs84=0,0,0
> data source : e:\PRISM\NetCDF\ppt_1981.nc
> names : X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14,
> X15, ...
> unknown : 1, 365 (min, max)
> varname : ppt
>
> The one is not working with above code has following information
> NetCDF file 2:
> class : RasterBrick
> *dimensions : 1386, 365, 505890, 585 (nrow, ncol, ncell, nlayers) *
> resolution : 1, 0.041666 (x, y)
> extent : 29584.5, 29949.5, -124.793, -67.04392 (xmin, xmax, ymin,
> ymax)
> coord. ref. : +proj=longlat +datum=WGS84
> data source : e:\UoIGriddedWeather\pr_1981.nc
> names : X49.3960227966309, X49.3543586730957, X49.3126907348633,
> X49.2710266113281, X49.2293586730957, X49.1876945495605, X49.1460266113281,
> X49.104362487793, X49.0626945495605, X49.0210304260254, X48.979362487793,
> X48.9376983642578, X48.8960304260254, X48.8543663024902, X48.8126983642578,
> ...
> degrees_north: 25.0630779266357, 49.3960227966309 (min, max)
> varname : precipitation_amount
>
> The dimension in the NetCDF file 2 is not correct. should be 585, 1386,
> 505890,365.
>
> Has someone encountered the same problem before? How to resolve this?
>
> Look forward suggestions and solutions.
>
> Thanks,
>
> Ping
>
> [[alternative HTML version deleted]]
>
>
>
> ------------------------------
>
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>
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