Displaying 20 results from an estimated 300 matches similar to: "2 dimensional interpolation from matlab to R"
2010 Feb 03
3
to convert a character string in time
hi,
I have my data time expressed in character string exple "5:20" (hour:min) and i want to convert these in times recognized by R. I have tried the POSIXct function:
balise07$Hour <- as.POSXIct(balise07$Hour)
but it didn't work.
Do you know why? Do you know how i can convert my string character in a real time?
Thanks
Karine HEERAH
Master 2 mention
2010 Jan 26
2
hdf files
hello,
I have a problem to open an hdf file. i have downloaded the package 'hdf5' as it was advised on R seek. But when i try to load the file, the R console sends me an eror message:
setwd("C:/Documents and Settings/Karine/Bureau/data/")
#install.packages('hdf5')
library("hdf5")
sea_ice <- hdf5load("asi-s6250-20090704-v5i.hdf", load =
2010 Apr 07
1
kriging problem - very urgent
Hi everybody,
I have a longitude vector and a latitude one. Associated to these coordinates, i have a matrix with some data at some coordinates but not all.
Lon <- seq(136.025,144.975,0.05)
Lat <- rev(seq(-66.975,-65.525,0.05))
dim(z) <- c(Lon,Lat)
And i have tried to apply to these data a kriging function. But first i need to reshape these 3 variables to have a dataframe
2010 Feb 23
3
difference between date and times
Hi,
I have date and time in a format like this: " 2007-02-21 05:19:00".
Do you which function i can use to derterminate the difference in time between this value and an other one.
For exemple:
this one : 2007-02-21 05:19:00
and this one : 2007-02-20 14:21:53
Thanks a lot,
Karine H.
_________________________________________________________________
2013 Jan 03
1
nls problem with iterations
Hi,
I am using the nls function and it stops because the number of
iterations exceeded 50, but i used the nls.control argument to allow for
500 iterations. Do you have any idea why it's not working?
fm1 <- nls(npe ~ SSgompertz(npo, Asym, b2, b3),
data=f,control=nls.control(maxiter=500))
Thanks for your help,
Cheers,
Karine.
2010 Apr 26
2
plot dates
hi everybody,
How can you plot some dates? I mean how can i have the tickmarks with the label of each date on my x axis?
The dates i use are in POSIXct format, i don't know if it matters.
thanks a lot
Karine
_________________________________________________________________
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2010 Jan 28
1
make a grid with longitude, latitude and bathymetry data
hi,
i have a longitude vector (x) a latitude vector (y) and a matrix of bathymetry (z) with the dimensions (x,y). I have already succeeded in plotting it with the image.plot (package 'field') and the contour functions.
But now, I want to make a grid in order to extract easily the bathymetry corresponding to a couple of longitude, latitude coordinates.
Do you know a function or a
2013 Jan 04
2
(no subject)
Hi,
I am using the nls function and it stops because the number of iterations
exceeded 50, but i used the nls.control argument to allow for 500
iterations. Do you have any idea why it's not working?
fm1 <- nls(npe ~ SSgompertz(npo, Asym, b2, b3),
data=f,control=nls.control(maxiter=500))
Error in nls(y ~ exp(-b2 * b3^x), data = xy, algorithm = "plinear", start =
c(b2 =
2010 Feb 03
4
contour function: changing colour according to different levels
Hi everybody,
I am using the contour function to draw isobares. And i would like to to bold contours for an interval of 500m and weak contour for an interval of 100m.
Can someone help me with this?
Thanks a lot
Karine
_________________________________________________________________
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2009 Nov 03
2
reshaping pairs of columns
Given a data frame consisting of a pointID and 12 pairs of (lat, long)
variables, with names
latA, longA, latB, longB, ... latL, longL, I want to reshape it into a
data frame with the structure
point source lat long
1 A ... ...
1 B ... ...
I've looked at reshape and plyr, but can't figure out how to do this.
Details of my data frame are below
2010 Sep 23
1
NetCDF file: adding a variable
I am trying to create a NetCDF file with bathymetry (a matrix) and then to
add a grid type (an integer) as variables.
This is the relevant part of the code:
library(ncdf)
wfile="my_file.nc"
msv=-10
grdtp=2
# Dimensions
d1=dim.def.ncdf("lon","degrees",as.double(lon))
d2=dim.def.ncdf("lat","degrees",as.double(lat))
# Variables
2013 Jan 16
4
Get a percent variable based on group
Dear all, I'd like to get a percentage variable based on a group, but without creating a new data frame.
For example:
data(iris)
iris$percent <-unlist(tapply(iris$Sepal.Length,iris$Species,function(x) x/sum(x, na.rm=TRUE)))
This does not work, I should have only three standard values, respectively for setosa, versicolor, and virginica. How can I do this?
MANY THANKS,
Karine
2010 Jul 25
2
3d topographic map
Hi All-
I would like to create a 3d topographic map using lat/lon and
z(height). I have been scouring the R help pages and have not located
the package I am looking for. Does anyone have a suggestion of package
that will work for this?
thanks-
sherri
2011 May 04
1
bivariate linear interpolation
Hi,
I have three matrices (X,Y,P) with the same dimension. The X,Y grid is
regular and I want to
perform linear interpolation to pick out certain points. In matlab
appropriate call is
something like
Pout=interp2(X,Y,P,Xout,Yout, method="linear")
where Xout and Yout are the locations where I want the Pout data
(typically a different grid).
(Scipy has this routine in
2008 May 29
1
akima interpolation and triangulation question
Dear all;
First of all, this is probably a more conceptual question than a
R-related one, but still want to give it a try. When working with the
interpolation function "interp" from the package akima and the
triangulation function "tri.mesh" from package tripack I've got NA's
for the interpolation and "error" for the triangulation. The data is
arranged in a
2010 Apr 11
0
cluster analysis :: urgent
hi,
how can i do cluster analysis on spatial data? (longitude & latitude)
Because i used the function clust of the clustTool package and it did'nt work at all:
cl <- clust(dv,3,method="hclustAverage",distMethod="euclidean")
thanks a lot
Karine HEERAH
Master 2 , océanographie et environnements marins
Université Pierre et Marie Curie (Paris 6)
2010 Oct 12
2
Memory limit problem
Dear List,
I am trying to?plot?bathymetry contours around the Hawaiian Islands using the
package rgdal and PBSmapping.? I have run into a memory limit when trying to
combine two fairly small objects using cbind().? I have increased the memory to
4GB, but am being told I can't allocate a vector of size 240 Kb.? I am running R
2.11.1 on a Dell Optiplex 760 with Windows XP.? I have pasted
2016 Sep 07
2
ACL wrong category user for group and group for user
Le 05/09/2016 à 10:23, Rowland Penny via samba a écrit :
> On Mon, 5 Sep 2016 09:38:56 +0200
> Sam via samba <samba at lists.samba.org> wrote:
>
>> Hello,
>>
>> If I try to set acl under windows, something very strange appears.
>>
>> For instance, if I set something for the user samuel I get this with
>> the command getfacl :
>>
2008 Apr 17
1
spatialpixelsdataframe
I have a spatialpixelsdataframe containing bathymetry data. Is it
possible to save this as something similar to the meuse.grid so it can
be loaded without having to run the spatial interpolation each time the
script is called?
I don't see a straightforward method in the sp documentation.
2009 Jul 13
1
Times series adjustment
Dear all,
I want make correction depth of a bathymetric data set.
To do so, I have the depth data set sample every second (a depth at each
second) in one hand, and in the other hand, I have a tide variation
level data set sample every 250 ms. The time register in each data sets
(tide and bathymetric) is express in seconds followinf this format :
hh:mm:ss.ss
I would like to rectify the depth