Displaying 20 results from an estimated 3000 matches similar to: "adding an image to a plot"
2007 Aug 13
4
vertically oriented color key in heatmaps
Hi, I have some data which I was plotting using image(). I wanted to
add a vertical color key to the plot and I found that heatmap.2 in
gplots does let me add a color key. However, I was thinking of a
vertical bar with the color range rather than the style that gplots
provides.
Is there any package (or code snippet) that would let me add a
vertical color key to an image() or heatmap
2004 Sep 15
1
fractal dimension of an image
Hello, I have a problem that I think can be solved in R but I'm not sure
how to tie things together.
I have a digital image of a crystal growth in 2 dimensions. And my aim
is to calculate the fractal dimension of the crystal. I was planning to
use the box counting method.
So I need to read in the image in R (for which I can use the pixmap or
rimage packages) and then draw a grid over at a
2007 May 14
2
creating a "list of 3 dataframes" from a "list of 2 dataframes" and a dataframe?
#I wish to create a "list of three dataframes" ("results2") from a "list of two dataframes" (temp) and a dataframe ("c")?
#Please advise.
a <- data.frame(x=c(1,2,3),y=c(5,7,9))
b <- data.frame(x=c(2,4,7,9),y=c(2,3,5,4))
c <- data.frame(x=c(22,34,7,9),y=c(52,63,5,4))
results1 <- list(a,b,c) #what I want
#but this is how I need to get there
2007 Aug 09
1
S4 based package giving strange error at install time, but not at check time
Hi, I have a S4 based package package that was loading fine on R
2.5.0 on both OS X and
Linux. I was checking the package against 2.5.1 and doing R CMD check
does not give any warnings. So I next built the package and installed
it. Though the package installed fine I noticed the following message:
Loading required package: methods
Error in loadNamespace(package, c(which.lib.loc, lib.loc),
2003 Nov 10
10
shuffling a vector
Hi,
I'me trying to write a function that will shuffle a vector. At the
moment I'm baically making a vector of randomized indices and then
making a new vector from the original one using these random indices.
However, is there an alternative (more elegant) method to do this? I
tried help.search('shuffle') but it does'nt return anything relevant.
Thanks,
2003 Nov 10
5
attaching data to any object
Hi,
is the following possible - in a given session I make a lot of objects
and save when exiting. Usually I note down seperately what each object
is about. Is it possible to attach data to any object which would
essentially be a short note explaining the meaning of it?
Thanks,
-------------------------------------------------------------------
Rajarshi Guha <rxg218 at psu.edu>
2005 May 26
5
a more elegant approach to getting the majority level
Hi, I have a factor and I would like to find the most frequent level.
I think my current approach is a bit long winded and I was wondering if
there was a more elegant way to do it:
x <- factor(sample(1:0, 5,replace=TRUE))
levels(x)[ which( as.logical((table(x) == max(table(x)))) == TRUE ) ]
(The length of x will always be an odd number, so I wont get a tie in
max())
Thanks,
2004 Feb 06
3
a grep/regexpr problem
Hi,
I'm trying to parse lines of the form:
dan001.hin (0): fingerprint={256, 411, 426, 947, 973, 976}
What I need is the sequence of number between {}. I'm using grep as
match <- grep("{([0-9,\s]*)}",s,perl=T,value=T)
where s is a character vector.
But all I get is the whole string s. I tried using regexpr in an attempt
to get just the sequence I wanted:
match <-
2003 Oct 02
4
using a string as the formula in rlm
Hi,
I am trying to build a series of rlm models. I have my data frame and
the models will be built using various coulmns of the data frame.
Thus a series of models would be
m1 <- rlm(V1 ~ V2 + V3 + V4, data)
m2 <- rlm(V1 ~ V2 + V5 + V7, data)
m3 <- rlm(V1 ~ V2 + V8 + V9, data)
I would like to automate this. Is it possible to use a string in place
of the formula?
I tried doing:
fmla
2003 Sep 03
3
plotting a distribution curves
Hi,
is there a way to plot distribution curves (say normal or chi sq etc)
from within R?
For example I looked up the *chisq family of functions but I'm not sure
as to how I would use them to generate a plot of the chi sq distribution
(for arbitrary d.o.f).
Thanks,
-------------------------------------------------------------------
Rajarshi Guha <rajarshi at presidency.com>
2003 Dec 03
3
checking for identical columns in a mxn matrix
Hi,
I have a rectangular matrix and I need to check whether any columns
are identical or not. Currently I'm looping over the columns and
checking each column with all the others with identical().
However, as experience has shown me, getting rid of loops is a good idea
:) Would anybody have any suggestions as to how I could do this job more
efficiently.
(It would be nice to know which
2004 May 20
2
column sorting a matrix with indices returned
Hi,
I'm trying to translate some Matlab code to R and I'm trying to
implement the behavior of Matlab's sort() which when applied to a matrix
will sort the columns returning the column sorted matrix as well as a
matrix of permuted indices.
Doing:
> x <- matrix(c(3,4,2,6,3,4,8,7,5), nr=3)
> x
[,1] [,2] [,3]
[1,] 3 6 8
[2,] 4 3 7
[3,] 2 4 5
2004 Mar 02
3
using object reference
Hi,
I have read the previous thread on using references to objects in a
function but the solution suggested does'nt seem to be working.
basically I have an object x which has an attribute a containing some
text. I would like to pass x to a function which will change the
attribute a with some new text and have the change visible when the
function exits.
something like
attr(x,'a')
2004 Mar 27
3
a question about scoping functions
Hi,
I've written some helper functions which are used by another function
(called func()). When func() is sourced I dont want the helper function
to be seen in the global namespace (as shown by ls()).
Currently what I have done is:
func <- function() {
helper1 <- function() {
...
}
helper2 <- function() {
...
}
# some code
}
Is there anyway to take the functions
2003 Oct 01
1
question about predictions with linear models
Hi,
this question is probably very obvious but I just cant see where I
might be going wrong.
I'm using the lm() function to generate a linear model and then make
predictions using a different set of data.
To generate the model I do (tdata & pdata are matrices of observations
and parameters, tdepv, pdepv are response vectors)
x <- as.data.frame(tdata)
x$tdepv <- tdepv
2003 Mar 03
2
saving a plot to a file
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hi,
I'm a new user of R and have managed to make a plot of a histogram. Is there
any way I set the title and axes labels and then save the plot as an image
(png/gif)?
Thanks
- --
- -------------------------------------------------------------------
Rajarshi Guha <rajarshi at presidency.com> <http://jijo.cjb.net>
GPG
2003 Nov 18
2
sampling without repetition
Hi,
I'm trying to write a function that will divide a given range of
numbers into 3 sets using sample(), without repetition. Currently I'm
trying this approach:
r <- 1:10
s1 <- sample(r,size=3)
Next, I want to remove the selected elements from r and sample() from
the remainder.
r <- r[ -(r=s1) ]
s2 <- sample(r,size=3)
When I go to remove the elements contained in s2 from
2003 Sep 30
2
subsetting a matrix
Hi,
I'm trying to take a set of rows and columns out of a matrix. I hve
been using the index aray approach. My overll matrix is X and is 179 x
65. I want to take out 4 columns and 161 rows.
Thus I made a 161 x 2 array I and filled it up with the row,col indices.
However doing,
X[ I ] gives me a vector of the extracted elements. Is there anyway I
can coerce this into a 161 x 4 matrix?
2005 Apr 04
5
a question about box counting
Hi,
I have a set of x,y data points and each data point lies between (0,0)
and (1,1). Of this set I have selected all those that lie in the lower
triangle (of the plot of these points).
What I would like to do is to divide the region (0,0) to (1,1) into
cells of say, side = 0.01 and then count the number of cells that
contain a point.
My first approach is to generate the coordinates of these
2004 Sep 15
2
efficient submatrix extraction
Hi,
I have a matrix of say 1024x1024 and I want to look at it in chunks.
That is I'd like to divide into a series of submatrices of order 2x2.
| 1 2 3 4 5 6 7 8 ... |
| 1 2 3 4 5 6 7 8 ... |
| 1 2 3 4 5 6 7 8 ... |
| 1 2 3 4 5 6 7 8 ... |
...
So the first submatrix would be
| 1 2 |
| 1 2 |
the second one would be
| 3 4 |
| 3 4 |
and so on. That is I want the matrix to be evenly divided