Displaying 20 results from an estimated 10000 matches similar to: "cell counting in R"
2007 Aug 23
4
Calculating diameters of cirkels in a picture.
Hi,
Maybe this is more a programming questions than a specific R-project question, but maybe there is someone who can point me in the right direction.
I have a picture of cirkels which I took with a digital camera.
Now I want to use the diameter of the cirkels on the picture for analysis in R.
I can use pixmap to import the picture, but how do I find the outside cirkels and calculate the
2009 Oct 27
1
Rjava, RImageJ, and/or S4 question.
I am out of my league with this question. The following code starts the java imaging program ImageJ from within R, and displays an image (assuming ImageJ is installed on your computer).
library(RImageJ)
img <- IJ$openImage( file.choose() ) #pick an available .tif file
img$show() # make the image object visible
# An image is now displayed
# find out about the objects involved
>
2010 Mar 08
2
black cluster in salt and pepper image
Hi,
on a lattice, I have binary 0/1 data. 1s are rare and may form clusters.
I would like
to know the size/length of largest cluster. Any help warmly welcome,
Sylvain.
2009 Sep 06
3
Video Analysis?
What software exists for digitizing video to quantify the motion
of specific features in the image? I might be willing to use something
that's NOT in R, though I'd prefer something in R (or at least with an R
intereface).
Thanks,
Spencer Graves
2009 Dec 08
2
automated image processing
Hi,
I am looking for a R package which is capable to process and analysis pictures of tissues (stained) in an automatic way.
I had a look on biops and EBImage (Bioconductor) but they are not automatic...
Did you already use/know a such package ?
Thanks,
- Martial
_________________________________________________________________
Tchattez en direct en en vidéo avec vos amis !
2003 Oct 05
3
Placing legends
I'm trying to automate making a bunch of figures and I need a way to
automate legend position. As I understand it the legend is placed based
on coordinates. I don't know before hand what the coordinates are going
to be. On one graph my y axis might go from -50 to -10. On another it
might go from 0 to 180.
Is there any way to query where the origin is? Or is there another way
to
2011 Sep 14
2
Image processing and analysis with R
Hello everyone,
I'm working in a project to create an special analysis about visualization in some animals and its behaviour, through checking eye movement. The point is this is very important to get data from the image as a resume of what this animal sees. I think an RGB histogram like photoshop does, but I need to get the data from this histogram analysis and I was wondering about using R
2009 Oct 17
2
Recommendation on a probability textbook (conditional probability)
I need to refresh my memory on Probability Theory, especially on
conditional probability. In particular, I want to solve the following
two problems. Can somebody point me some good books on Probability
Theory? Thank you!
1. Z=X+Y, where X and Y are independent random variables and their
distributions are known.
Now, I want to compute E(X | Z = z).
2.Suppose that I have $I \times J$ random number
2006 Apr 11
1
type II and III Sum square whit empty cells
Dear all
I need to run an anova from a factorial model
y_{ijk}=\alpha_i+\beta_j+(\alpha\beta)_{ij}+e_{ijk}
and calculate type II and III sums of square, but I have an empty
cells, so anova function from package car fail. (I believe)
y<-c(7,13,6,10,8,11,8,3,7,5,65)
a<-as.factor(c(1,1,2,2,3,3,3,1,1,1,2))
b<-as.factor( c(rep(1,7),rep(2,4)) )
table(b,a) # cell (2,3) is empty
2009 Dec 03
1
count number of empty cells in a table/matrix/data.frame
Hi everyone!
This is a ridiculously simple problem, I just can't seem to find the
solution!
All I need is something equivalent to
sum(is.na(x))
but instead of counting missing values, to count empty cells (with a value
of 0).
A naive attempt with is.empty didn't work :)
Thanks!
Maja
Oh, and if the proposed solution would be to make all the empty cells into
missing cells, that is
2009 Jan 08
1
cosinor analysis
Hallo,
I didn´t found any facilities for Halbergs cosinor analysis in R. This analysis is well known in the Chronobiology as the least square approximation of time series using cosine function of known period (in my case of 24hours-period). I tried to write a script but crashed...
Can you give me some advices, please!?
Thanks
Anne Berger
Institute of Zoo- and Wildlife Research, Berlin, Germany
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 Nov 23
2
IFELSE across large array?
Dear all,
As our previous email did not get any response, we try again with a
reformulated question!
We are trying to do something which needs an efficient loop over a huge
array, possibly functions such as apply and related (tapply,
lapply...?), but can't really understand syntax and examples in
practice...i.e. cant' make it work.
to be more specific:
we are trying to apply a mask
2000 Sep 20
2
Image analysis in R?
As far as I can tell, there are no facilities in the "base" R for image
analysis. Is there any extension or package for R that implements
image analysis? I'm thinking of features such as
o Reading and writing image files,
o displaying indexed or "true color" images,
o resizing, cropping, etc, of images,
o filters for manipulating images (smoothing, edge detection, etc)
o
2011 Aug 26
1
matrix bands
Dear R developers,
I was looking for a function analogous to base::diag() for getting and
setting bands of a matrix. The closest I could find was Matrix::band(),
but this was not exactly what I wanted for two reasons. Firstly,
Matrix::band() returns a matrix rather than just the specified band.
Secondly, Matrix::band() cannot be used for setting the values for a
matrix band.
Setting or
2011 Apr 27
6
Assignments inside lapply
Dear all I would like to ask you if an assignment can be done inside a lapply statement.
For example
I would like to covert a double nested for loop
for (i in c(1:dimx)){
for (j in c(1:dimy)){
Powermap[i,j] <- Pr(c(i,j),c(PRX,PRY),f)
}
}
to something like that:
ij<-expand.grid(i=seq(1:dimx),j=(1:dimy))
unlist(lapply(1:nrow(ij),function(rowId) { return
2009 Apr 16
3
Digitizing the Plot
Hi R,
Wanted to check if there are any packages available for getting the
(x,y) data points of a graph or a plot, which is in the image format.
Say, the plot could be a published report, and I want to get the points
of the curve plotted. (I am speaking something related the subject
discussed in http://www.uniphiz.com/digitizing.htm)
Thanks,
Shubha
This e-mail may contain
2003 Apr 02
2
lme parameterization question
Hi,
I am trying to parameterize the following mixed model (following Piepho
and Ogutu 2002), to test for a trend over time, using multiple sites:
y[ij]=mu+b[j]+a[i]+w[j]*(beta +t[i])+c[ij]
where:
y[ij]= a response variable at site i and year j
mu = fixed intercept
Beta=fixed slope
w[j]=constant representing the jth year (covariate)
b[j]=random effect of jth year, iid N(0,sigma2[b])
a[i]=random
2010 Feb 08
3
Hypercube in R
Dear all,
Does anybody have an idea or suggestion how to construct (plot)
4-dimensional hypercube in R.
Thanks in advance for any pointers.
Regards, Andrej
2007 May 25
1
Speeding up resampling of rows from a large matrix
I'm trying to:
Resample with replacement pairs of distinct rows from a 120 x 65,000
matrix H of 0's and 1's. For each resampled pair sum the resulting 2
x 65,000 matrix by column:
0 1 0 1 ...
+
0 0 1 1 ...
_______
= 0 1 1 2 ...
For each column accumulate the number of 0's, 1's and 2's over the
resamples to obtain a 3 x 65,000 matrix G.
For those