[R-sig-Geo] Help

Bakary Faty b@k@ry|@ty @end|ng |rom gm@||@com
Mon Jan 13 10:39:07 CET 2020 

Dear Silver,

Thank for your help.

I think there had been a mix-up in the Coordinate Rference System. When I
plot this shapefile I get
it in the UTM Coordinate.
Le Senegal is in Zone 28 North. The watershed on what I work is shared by
trois Countries (Senegal, Gambie and Guinea).
But in the choose of UTM 33 in my script is an error.
Thank very much.

Best regards


Le lun. 13 janv. 2020 à 07:22, Micha Silver <tsvibar using gmail.com> a écrit :

> Hello Bakary:
>
> Please keep questions on the list, so that others can benefit from the
> conversation.
>
>
> I see that the Basins shapefile you sent is declared to be in Long/Lat
> WGS84 Coordinate Reference System, however the coordinates (the X-Y
> locations) look like it is already projected to UTM 33. Is it possible
> there is some mixup in the Coordinate Reference System of the Basins
> shapefile?
>
> (That would explain why the basins layer does not appear on your plot)
>
>
> Furthermore, I think that you are working in Senegal/Gambia (from the
> coordinates in the DATAFILE). If so, why did you choose to project to UTM
> 33 in your script? Isn't Senegal in UTM zone 28?
>
>
> Attached is the corrected script (changed to UTM28). The corrected basin
> shapefile is sent privately. (too big for the list)
>
>
> Regards, Micha
>
>
>
>
> On 12/01/2020 21:29, Bakary Faty wrote:
>
> Dear Micha Silver
>
> I'm writing you this email following your contribution on my isohyet map
> code, in 'r-sig-geo'.
>
> I really appreciated your help which helped me a lot. I can draw the
> isohyets but I can't draw the contour of my study basin.
>
> You can see where the problem is in the code to make a change again?
>
> You will find the files of the watershed and my code R attached.
>
> Thank you very much by advance
>
>
> Best regards
>
> Le ven. 10 janv. 2020 à 09:41, Micha Silver <tsvibar using gmail.com> a écrit :
>
>>
>> On 09/01/2020 21:02, Bakary Faty wrote:
>> > Thank you for appreciated reply,
>> >
>> > I explane you exactly what I want to do with this R code attached.
>> > I want to adapt this code to my data to build an isohyet map.
>> > But i have some difficulties to adapt it to my case.
>> > I will be very happy when you will help my to adapt this R code
>> (attached)
>> > to my case.
>> > You can find attached the you R code and my data file.
>> > Best regards
>> >
>>
>>
>> I made two small changes in your code, and it works fine:
>>
>>   * First I used the suggestion (earlier in this thread) to create your
>>     grid.
>>   * Then, you had an error in your call to autoKrige.
>>   * After getting that right, I created isohyetal lines with
>> rasterToContour
>>
>> Here's my version
>>
>>
>> library(automap)
>> library(raster)
>> library(rgdal)
>>
>> ## READ INPUT FILE
>> rain_data <- read.csv(file="DATAFILE_FOR_ISOHYET.csv")
>>
>> point_coords <- rain_data[c("Lon","Lat")]
>> coordinates(rain_data) <- point_coords
>> p4str <- CRS("+init=epsg:4326")
>> proj4string(rain_data) <- p4str
>>
>> ## CONVERTION TO UTM
>> p4str_UTM <- CRS("+init=epsg:32633")
>> rain_data_UTM <- spTransform(rain_data, p4str_UTM)
>>
>>
>> bb <- bbox(rain_data_UTM)
>> minx <- bb[1,1]
>> maxx <- bb[1,2]
>> miny <- bb[2,1]
>> maxy <- bb[2,2]
>>
>> ## EACH PIXEL WILL BE 1000 METERS
>> pixel <- 1000
>> grd <- expand.grid(x=seq(minx, maxx, by=pixel), y=seq(miny, maxy,
>> by=pixel))
>> coordinates(grd) <- ~x+y
>> gridded(grd) <- TRUE
>> proj4string(grd) <- p4str_UTM
>>
>>
>> ## KRIGING, USING AUTOKRIGE WHICH CREATES A BEST GUESS VARIOGRAM
>> # OK_rain <- autoKrige(Rainfall_value ~ 1, rain_data_UTM, grd)
>> # There is no variable "Rainfall_value" in your data,
>> # It is called RAIN_DATA
>> OK_rain = autoKrige(formula = RAIN_DATA ~1,
>>                      input_data = rain_data_UTM,
>>                      new_data = grd)
>>
>> ## TRASFORM TO RASTER
>> rain_rast <- raster(OK_rain$krige_output)
>>
>> summary(rain_rast)
>>
>>
>> # Minimumn is 540, max is 1735
>> # So create isohyetal lines about every 100 mm and plot
>>
>> isohyets = rasterToContour(rain_rast, nlevels = 12)
>> plot(rain_rast)
>> lines(isohyets, add = TRUE)
>>
>>
>> > Le jeu. 9 janv. 2020 à 18:41, Bakary Faty <bakaryfaty using gmail.com
>> > <mailto:bakaryfaty using gmail.com>> a écrit :
>> >
>> >     Thank you for appreciated reply,
>> >
>> >     I explane you exactly what I want to do with this R code attached.
>> >     I want to adapt this code to my data to build an isohyet map.
>> >     But i have some difficulties to adapt it to my case.
>> >     I will be very happy when you will help my to adapt this R code
>> >     (attached)
>> >     to my case.
>> >     You can find attached the you R code, my data file and my sahefile
>> >     of watershed.
>> >
>> >     Best regards
>> >
>> >
>> >     Le jeu. 9 janv. 2020 à 17:47, Ben Tupper <btupper using bigelow.org
>> >     <mailto:btupper using bigelow.org>> a écrit :
>> >
>> >         Welcome to r-sig-geo!
>> >
>> >         I don't think that you haven't provided us enough information
>> >         so that we can help.  On the other hand, does the example
>> >         below using expand.grid help?
>> >
>> >         minx <- 20
>> >         maxx <- 25
>> >         miny <- 31
>> >         maxy <- 36
>> >         pixel <- 1
>> >         grd <- expand.grid(x = seq(minx, maxx, by=pixel), y =
>> >         seq(miny, maxy, by=pixel))
>> >
>> >         Ben
>> >
>> >         On Thu, Jan 9, 2020 at 11:41 AM Bakary Faty
>> >         <bakaryfaty using gmail.com <mailto:bakaryfaty using gmail.com>> wrote:
>> >
>> >
>> >             Dear,
>> >
>> >             I'm writing to express my wish to join R-sig-geo list users.
>> >             I was doing a search on the net to know how to build an
>> >             isohyet map and I came across this R code.
>> >             However, I stumbled upon a problem from the line :
>> >             grd <- expand.grid(x=seq(minx, maxx, by=pixel),
>> >             y=seq(miny, maxy, by=pixel)),
>> >             I get the following error message:
>> >             default method not implemented for type 'S4'. I want to
>> >             know how resolve this error.
>> >
>> >             Also, I would like to ask you only at the line level:
>> >             minx <- rain_data_UTM at bbox[1,1]
>> >             maxx <- rain_data_UTM at bbox[1,2]
>> >             miny <- rain_data_UTM at bbox[2,1]
>> >             maxy <- rain_data_UTM at bbox[2,2],
>> >             if I should limit myself to "rain_data_UTM" or write
>> >             completely:
>> >             rain_data_UTM at bbox[,].
>> >              By the way, this is the pointfile I reconstructed.
>> >             You can find it attached to the mail.
>> >
>> >             Thanks in advance
>> >
>> >             Best regards
>> >
>> >
>> >
>> >             Bakary
>> >             _______________________________________________
>> >             R-sig-Geo mailing list
>> >             R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>> >             https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>> >
>> >
>> >
>> >         --
>> >         Ben Tupper
>> >         Bigelow Laboratory for Ocean Science
>> >         West Boothbay Harbor, Maine
>> >         http://www.bigelow.org/
>> >         https://eco.bigelow.org
>> >
>> >
>> >
>> >     --
>> >
>> >
>> >
>> >     Bakary
>> >
>> >
>> >
>> > --
>> >
>> >
>> >
>> > Bakary
>> >
>> > _______________________________________________
>> > R-sig-Geo mailing list
>> > R-sig-Geo using r-project.org
>> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>> --
>> Micha Silver
>> Ben Gurion Univ.
>> Sde Boker, Remote Sensing Lab
>> cell: +972-523-665918
>> https://orcid.org/0000-0002-1128-1325
>>
>>
>
> --
>
>
>
> Bakary
>
> --
> Micha Silver
> Ben Gurion Univ
> Sde Boker, Remote Sensing Lab
> +972-523-665918
>
>

-- 



Bakary

	[[alternative HTML version deleted]]

More information about the R-sig-Geo mailing list