Displaying 20 results from an estimated 30000 matches similar to: "defining an array with one of the elements being a vector"
2010 Nov 14
2
replace a row in a matrix
Dear all,
I created a n*2 matrix and I want to replace the ith row with a vector. Can
anyone suggest me what is the simple way to do it? Sorry for bothering you
with such simple question. I appreciate any hints or advice.
Thanks in advance.
Cassie
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2011 Feb 14
2
how to overlay a map of US on image plot
Dear all,
I have a data set which has latitude, longitude (not in increasing order)
and observed precipitation corresponding to those locations. I am using
image.plot command for that. But I want to overlay a map of US on that plot.
I know we can use map('usa') to draw it, but I dont know how can I overlay
it on the plot of the precipitation data. Can anyone please help me with it?
2010 Nov 09
2
simulation from pareto distn
Dear all,
I am trying to simulate from truncated Pareto distribution. I know there is
a package called PtProcess for Pareto distribution...but it is not for
truncated one. Can anyone please help me with this?
Thanks in advance.
Cassie
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2011 Apr 08
4
Simulation from discrete uniform
Dear all,
I am trying to simulate from discrete uniform distribution. But I could not
find any in-built code in R. Could anyone help me please?
Thanks in advance for the time and help.
Cassie
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2012 Apr 10
1
how to convert seconds to 12 hour time format
Hello everyone,
I am wondering if there is any routine in R which can convert time given in
'seconds' unit to the 12 hour time format. For example, suppose the data
set looks like
x=c(36885,84000,20) #x in seconds
I want to get the output as
[1] " 11:14:45 AM"
[2] " 11:20:00 PM"
[3] "12:20:00 AM"
Does anyone have any idea? Thanks in advance.
Cassie
2011 Aug 01
3
General indexing in multidimensional arrays
Dear R community,
I have a general question regarding indexing in multidiemensional arrays.
Imagine I have a three dimensional array and I only want to extract on
vector along a single dimension from it:
data <- array(rnorm(64),dim=c(4,4,4))
result <- data[1,1,]
If I want to extract more than one of these vectors, it would now really
help me to supply a logical matrix of the
2010 Dec 16
5
test whether all elements of a vector are identical
Dear list,
this might be an easy one, but I could figure out a solution (or how to
google the right term).
Is there any way to test whether all elements of a vector are identical?
For numeric vectors I would use
sum(diff(vector)==0)==0
but I have character vectors. Any Ideas?
Cheers
Jannis
2010 Sep 29
1
executing loop
Dear All,
I am trying to define a loop for a m*n matrix, where i=1:n and j=1:m. Unlike
the usual for loop, i should go in the following way:
For j=1,
i=1,2,3,....n
For j=2,
i=n,n-1,n-2,......,1
For j=3,
i=1,2,3,.....n etc.
which means i should go in either increasing or decreasing order
alternatively.
Can anyone please help me in doing this?
Thanks,
Cassie
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2010 Jul 29
2
Fry Plots
Does anyone know how to do a fry plot in R? I have 600-800 points per image, and I really don't want to attempt that manually.
Thank you!
Cassie
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2010 Nov 27
1
return vector of element names for vector, matrix or array
Just as as.vector() takes a vector, matrix or array and returns a
vector in row-major order,
I'd like to write a function to take such an object and return the
dimension names,
pasted with some separator, as a similar vector.
Here is something ugly cobbled together to demonstrate what I want: a
function to work
for any number of dimensions.
vecnames <- function(x, sep=':') {
2011 Jul 27
2
for loop help
I am having a hard time putting the below into a loop, where it pulls out ppt from all he stations I have versus having to go through and hard code the data to the specific stations. I tried
stnID <- stnid[which(duplicated(stnid)==FALSE)]
for(i in 1:length(stnID))
{
ppt[i] <- ppt[which(stnid==[i])]
}
but it doesn't like to use the which function inside a for loop? Any idea's here is
2011 May 16
1
simulation from truncated poisson
Dear all,
I need to simulate values from a Poisson distribution which is truncated at
certain value 'a'. Can anyone tell me if there is in-built package in R
which can simulate from a truncated Poisson? If not, what should be the
steps to write a function which would do that?
Thanks in advance.
Cassie
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2011 Jul 21
1
replacing duplicate rows
Hi all,
I have a matrix which looks like the following,
x=matrix(c(1,2,3,4,3,5,4,6,4,9),5,2,byrow=T)
Now, I want to replace the 2nd columns of those 4 rows which have duplicate
entries in the 1st column. For example, x[2,1]=x[3,1]=3 and I want to
replace x[3,2] by x[2,2]. Similarly, I want to replace x[5,2] with x[4,2],
which means that for duplicate entries in the 1st column, I want to replace
2012 Apr 26
2
problem with break command
Hello R-users,
I am having a problem with the 'break' command in R. I am wondering if
anyone can help me out with this. My program is similar to the following.
a=rep(NA,5)
a[1]=0
for(i in 2:5)
{
a[i]=a[i-1]+runif(1,0,3)
if(a[i]>5)
{
i=2
break
}
}
What exactly I am trying to do is find the sequence 'a' where the
individual values of 'a'
2013 Apr 10
1
problem with the image command
Hello R-users,
I am trying to do an image plot where I have been given latitudes,
longitudes and the values at the corresponding locations. A sample of the
data is given as follows:
values=c(0,1,0,0,0,0,2,2,0,0)
lat=c(29.6660,29.6756,29.3492,29.2654,29.2827,29.4070,35.3510,35.6590,35.7587,38.2794)
2011 Mar 07
1
help needed with histogram plotting
Dear all,
I am trying to plot 3 histograms on the same graph using the following
command.
hist(x,xlim=c(0,100))
hist(y,add=TRUE)
hist(z,add=TRUE)
The xlim of y is c(20,21) and that of z is c(99,99.5) , whereas the variable
x has xlim at c(0.5,2). Apparently, the graph end of displaying a line only,
corresponding to each histogram due to the wide range of the xlim and
tightness of the
2005 Apr 19
2
indexing an array using an index-array, but one entry being ', '
Hi
I have the following array:
test <- array(c(1:16), dim = c(3,4,3))
test
## I call some enries using an index array
test.ind <- array(rbind(c(1,2,1), c(3,3,2)), dim = c(2,3))
test[test.ind]
## suppose I want all values in the 2nd row and 4th col over
## all three 3rd dimensions
test[2,4,]
how to specify a test.ind array with the last index left with ',' i.e
test.ind should be
2011 Jun 17
1
issue with strptime
Hi everyone,
I have bunch of date and time observations in the format %Y-%m-%d %I %M %S
%p. I used strptime() to read this format. But the problem is some of the
times are in the format of %I %M %p, so for those times, strptime is giving
me NA values.
For example,
strptime(paste("2009-04-08","1:49:47 PM"),format="%Y-%m-%d %I:%M:%S %p")
[1] "2009-04-08
2011 May 26
2
summing array elements
Hi to everybody
I have an array with dimensions 2,4,3,3.
Wanting to sum the matrices in the first two dimensions, I'm trying to use
the "apply" function, but with no results. Have to say I'm quite new with R
syntax.
tx in advance
marco
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2010 Mar 24
1
lattice: defining graphical parameters
Dears,
could anyone give me some advice how to change some plotting parameters for a lattice graph?
I need to adjust the following:
-reduce outer margins (like par(mar=c(0,0,0,0)) with base graphs)
-modify positions of labels (like par(mpg=c(0,0,0)) with base graphs)
I already did some research, but got confused by the huge amount of settings with the lattice objects.
I know that the road