Displaying 20 results from an estimated 300 matches similar to: "gridding values in a data frame"
2009 May 11
2
Plotting colors on a world map
Hi useR's
I have created a simple map of the world using the following code:
m <- map(xlim=c(-180,180), ylim=c(-90,90))
map.axes()
I then create a grid of dimension 36x72 using the code:
map.grid(m, nx=72, ny=36, labels=FALSE, col="black")
This gives 2592 grid cells. In a separate data set of dimension 36x72, I
have 2592 temperature values (some missing values are present)
2007 Sep 10
5
finding the minimum positive value of some data
useRs,
I am looking to find the minimum positive value of some data I have.
Currently, I am able to find the minimum of data after I apply some other
functions to it:
> x
[1] 1 0 1 2 3 3 4 5 5 5 6 7 8 8 9 9 10 10
> sort(x)
[1] 0 1 1 2 3 3 4 5 5 5 6 7 8 8 9 9 10 10
> diff(sort(x))
[1] 1 0 1 1 0 1 1 0 0 1 1 1 0 1 0 1 0
> min(diff(sort(x)))
[1] 0
2008 Jul 29
3
finding a faster way to do an iterative computation
useR's,
I am trying trying to find out if there is a faster way to do a certain
computation. I have successfully used FOR loops and the apply function to
do this, but it can take some time to fully compute, but I was wondering if
anyone may know of a different function or way to do this:
> x
[1] 1 2 3 4 5
> xk
[1] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
I want to do:
2008 Jul 24
2
simple random number generation
useR's,
I want to randomly generate 500 numbers from the standard normal
distribution, i.e. N(0,1), but I only want them to be generated in the range
-1.5 to 1.5. Does anyone have a simple way to do this?
Thanks,
dxc13
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2008 Jan 16
3
color ranges on a 2D plot
useR's
I am trying to color the points on a scatter plot (code below) with two
colors. Red for values 0.5 -1.0 and blue for 0.0 - .49. Does anyone know a
easy way to do this?
x <- runif(100, 0, 1)
y <- runif(100, 0, 1)
plot(y ~ x, pch=16)
Thanks,
dxc13
--
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Sent from the R help
2009 May 24
2
Deleting columns from a matrix
useR's,
I have a matrix given by the code:
mat <-
matrix(c(rep(NA,10),1,2,3,4,5,6,7,8,9,10,10,9,8,NA,6,5,4,NA,2,1,rep(NA,10),1,2,3,4,NA,6,7,8,9,10),10,5)
This is a 10x5 matrix containing missing values. All columns except the
second contain missing values. I want to delete all columns that contain
ALL missing values, and in this case, it would be the first and fourth
columns. Any column
2009 May 04
2
A variation on the bar plot
Hi all,
I cannot think of the technical name of this plot, but I want to create a
plot with the data below that looks like two back-to-back horizontal bar
plots.
Ideally, there would be a vertical line in the center of the plot at zero,
and on the right hand side would be 4 bars representing the values for 2007,
and on the left side of the vertical line would be the corresponding values
for 2005.
2009 May 19
3
how to calculate means of matrix elements
useR's,
I have several matrices of size 4x4 that I want to calculate means of their
respective positions with. For example, consider I have 3 matrices given by
the code:
mat1 <- matrix(sample(1:20,16,replace=T),4,4)
mat2 <- matrix(sample(-5:15,16,replace=T),4,4)
mat3 <- matrix(sample(5:25,16,replace=T),4,4)
The result I want is one matrix of size 4x4 in which position [1,1] is the
2007 Sep 17
2
how to compare 2 numeric vectors
useR's
I am trying to compare two vectors that have the same length. More
specifically, I am interested in comparing the corresponding positions of
each element in the vector.
Consider these two vectors of length 20:
v1 <- 2 2 4 NA NA NA 10 NA NA NA NA NA NA NA NA NA NA
NA NA NA
v2 <- NA 4 NA NA NA NA 10 NA NA NA NA NA NA NA NA NA NA
NA
2008 Feb 21
3
applying a function to data frame columns
useR's,
I want to apply this function to the columns of a data frame:
u[u >= range(v)[1] & u <= range(v)[2]]
where u is the n column data frame under consideration and v is a data frame
of values with the same number of columns as u. For example,
v1 <- c(1,2,3)
v2 <- c(3,4,5)
v3 <- c(2,3,4)
v <- as.data.frame(cbind(v1,v2,v3))
uk1 <- seq(min(v1) - .5, max(v1) + .5,
2008 Aug 30
1
help with "persp" function
Dear List,
I am trying to draw a rectangular plane using the persp function, however I
can't seem to get it to work. I want the length along x1 axis to be between
1 and 3 and the length along the x2 axis to be between 1 and 4. All z
values for x1 should be equal (say, z=1) because this is a plane, not a
cube. Below is my current code. Any help is appreciated
Thanks in advance
dxc13
x
2009 May 13
4
plotting a grid with color on a map
Hi all,
I have posted similar questions regarding this topic, but I just can't seem
to get over the hump and find a straightforward way to do this. I have
attached my file as a reference.
Basically, the attached file is a 5 degree by 5 degree grid of the the world
(2592 cells), most of them are NA's. I just want to be able to plot this
grid over a world map and color code the cells. For
2008 Feb 20
2
intersecting rows of a matrix
useR's,
First, I would like to say thanks to John Fox for providing this segment of
code to perform intersection for multiple sets:
intersection <- function(x, y, ...){
if (missing(...)) intersect(x, y)
else intersect(x, intersection(y, ...))
}
I want to execute this function on the rows of a matrix I have:
Ik.mat.test <- matrix(c(2,3,6,1,2,6,6,1,2),byrow=T,nrow=3)
> Ik.mat.test
2007 Dec 18
3
creating a database
useR's,
I am writing a program in which the input can be multidimensional. As of
now, to hold the input, I have created an n by m matrix where n is the
number of observations and m is the number of variables. The data that I
could potentially use can contain well over 20,000 observations.
Can a simple matrix be used for this or would it be better and more
efficient to create an external
2008 Jan 11
1
matching values in a list
useR's,
I want to match the real number elements of a list that has 3 matrices as
its elements and then average those numbers. I think I am close, but I
can't get it to quite work out. For example,
> a <- list(matrix(c(10,NA,NA,12,11,
> 10,13,NA,14,12),ncol=2),matrix(c(10,12,15,13,11,
> 13,NA,NA,12,10),ncol=2),matrix(c(10,15,NA,13,NA, 13,12,NA,NA,10),ncol=2))
> a
[[1]]
2008 Oct 24
1
Errors in R CMD check for R 2.8.0
useR's,
I get these 2 errors when I run "R CMD check" on my package, and I cannot
figure out how to get around them. Does anyone have any ideas? If it is of
any help, I use Windows XP.
...
* checking replacement functions .... OK
* checking foreign function calls ... OK
* checking R code for possible problems ... NOTE
Error in inDL(x, as.logical(local), as.logical(now), ...):
2008 Sep 05
1
smoothing with the Gaussian kernel
useR's,
Does anyone know what function or package allows one to specify use of the
Gaussian kernel to smooth a data set, or is this just the default for most
functions?
Thanks,
dxc13
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2009 Nov 25
1
interior and exterior colors of a map
Hi useR's,
I have an image plot I want to overlay a map of the United States on, via
map('usa'). The image is basically a large rectangular of various colors.
When I overlay the United States map, the full rectangle of the image plot
is visible, but I only want to display the image WITHIN the United States
boundary.
Does anyone know a way to do this?
Thanks in advance,
dxc13
--
2007 Dec 24
2
expand.grid function
useR's,
I have used expand.grid() several times and like the results it gives me. I
am now trying something with it that I have not been able to get to work.
For any n column matrix I would like to run this function on those n columns
and store the results.
For example, if my matrix has 1 column then this is just expand.grid(x =
column1). If my matrix has two columns, then I want
2008 Jan 30
1
re stricting points in a data frame
useR's,
Consider some variables and a data frame of points:
x1 <- c(1,2,3)
x2 <- c(3,4,5)
xk1 <- seq(min(x1)-.5, max(x1)+.5,.5)
xk2 <- seq(min(x2)-.5, max(x2)+.5,.5)
expand.grid(xk1=xk1,xk2=xk2)
xk1 xk2
1 0.5 2.5
2 1.0 2.5
3 1.5 2.5
4 2.0 2.5
5 2.5 2.5
6 3.0 2.5
7 3.5 2.5
...
46 2.0 5.5
47 2.5 5.5
48 3.0 5.5
49 3.5 5.5
I want to restrict the data frame to only contain