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 <[email protected]
<mailto:[email protected]>> 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 <[email protected]
<mailto:[email protected]>> 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
<[email protected] <mailto:[email protected]>> 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
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--
Ben Tupper
Bigelow Laboratory for Ocean Science
West Boothbay Harbor, Maine
http://www.bigelow.org/
https://eco.bigelow.org
--
Bakary
--
Bakary
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Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
https://orcid.org/0000-0002-1128-1325
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