Displaying 6 results from an estimated 6 matches for "readasciigrid".
2012 Mar 05
1
Error in file(fname, "r") : invalid 'description' argument when running maptools' readAsciiGrid on a dataframe
...e a sum of differences between two ascii grids.
I have the file names of the two grid files in a data.frame along with
other data. I'm then trying to add a new column to the data.frame with
the result of that calculation.
eg.
library(maptools)
difcount <- function(surfA, surfB) {
A <- readAsciiGrid(surfA, colname="a")
B <- readAsciiGrid(surfB, colname="b")
sum(A$a - B$b)
}
attach(mydataframe)
difcount(surfA[1],surfB[1]) #this test part works fine and gives me
the correct result
#But when I try to do a batch job by running the function against each
row of the table...
2010 Sep 24
2
Reading in .aux (ESRI raster files) into R
Dear All,
I'v tried to read in data in numerous ways including:-
Spain10km<-data.frame(readAsciiGrid("F://RMap//sp10kpointid1.aux"))
Error in readAsciiGrid("F://RMap//sp10kpointid1.aux") :
object 'cellsize' not found
In addition: Warning message:
In readLines(t, n = 6) :
incomplete final line found on 'F://RMap//sp10kpointid1.aux'
Spain10km<-data.frame(...
2007 Mar 27
1
"Groups" in XYPLOT
...sired end result is a single xy plot of two separate (but similar in
values and ranges).
Full code follows, xyplot code at bottom
#########Determine Frequencies
##########coastal_slope
#needs the maptools package to read ESRI grid
require(maptools)
#import the flow slope grid
basin.map <- readAsciiGrid("C:/R_PLots/coastal_slp.asc", colname="slope")
basin_slope <- (basin.map$slope)
#read the slopes into a dataframe
freqs<-as.data.frame(table(basin_slope))
#rank the frequencies based on each unique occerence, note, ranks from 1 to
n
r<-rank(freqs$basin_slope)
n<-leng...
2013 Jan 27
1
lapply and SpatialGridDataFrame error
...have a set of 54 files that I need to convert from ASCII grid
format to .shp files to .bnd files for BayesX.
I have the following R code to operate on those files:
library(maptools)
library(Grid2Polygons)
library(BayesX)
library(BayesXsrc)
library(R2BayesX)
readfunct <- function(x)
{
u <- readAsciiGrid(x)
}
modfilesmore <- paste0("MaxFloodDepth_", 1:54, ".txt")
modeldepthsmore <- lapply(modfilesmore, readfunct)
maxdepth.plys <- lapply(modeldepthsmore, Grid2Polygons(modeldepthsmore,
level = FALSE))
layers <- paste0("examples/floodlayers_", 1:54)
polysha...
2006 Oct 10
1
How to assign a rank to a range of values..
>From the following:
basin.map <- readAsciiGrid("c:/temp/area.asc", colname="area")
I have a SpatialGridDataFrame which has the x and y cordinate of a cell, and
the drainage area of that cell. There are many cells with a low drainage
area (in my case, 33000 with an area of 37.16) and one cell with the highest
drainage area...
2012 Jul 04
3
Please help
...r=var.def.ncdf("mr","mm",list(x,y,t),-99.00,
longname="monthly rainfall")
#create ncdf file
ncnew=create.ncdf("rainfall.nc", varmr)
#read input
files=list.files(pattern=".asc")
mrain=matrix(0:0,0,3)
for(i in files)
{rainfall=data.frame(readAsciiGrid(i))
mrain=cbind(mrain,rainfall)
}
put.var.ncdf(ncnew, mrain)
close.ncdf(ncnew)
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Many thanks,
Jun
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