similar to: How to get the number of modes using kde2d

Displaying 20 results from an estimated 4000 matches similar to: "How to get the number of modes using kde2d"

2008 Oct 04
0
difference between sm.density() and kde2d()
Dear R users, I used sm.density function in the sm package and kde2d() in the MASS package to estimate the bivariate density. Then I calculated the Kullback leibler divergence meassure between a distribution and the each of the estimated densities, but the asnwers are different. Is there any difference between the kde2d and sm.density estimates? if there is a difference, then which is the best
2002 Oct 15
5
Specification change requests
Hi, as Conrad suggested, I've made a complete list of all points in the specification, which I beleive are errors, or where the explanation is unclear, contains unneccessary steps and so on. I hope someone has time to look through the points and if and when accepting or rejecting them be so very kind and inform me about it. I will also once again try to work through the residue
2002 Sep 23
2
More errors in the file format specification Was: Test files for decoder implementation
Hi, I've found some more errors in the file format specification (or at least points, where the specification and actual libvorbis implementation mismatch): - Floor 1 / curve computation / step 1: amplitude value synthesis 21) vector [floor1_final_Y] element [i] = [predicted] - (([val] - 1) divided by 2 using integer division) hould be: 21) vector [floor1_final_Y] element [i] =
2007 Aug 10
1
kde2d error message
Hello! I am trying to do a smooth with the kde2d function, and I'm getting an error message about NAs. Does anyone have any suggestions? Does this function not do well with NAs in general? fit <- kde2d(X, Y, n=100,lims=c(range(X),range(Y))) Error in if (from == to || length.out < 2) by <- 1 : missing value where TRUE/FALSE needed Thanks in advance!! Jen [[alternative
2009 Dec 02
2
Joint density kde2d works improperly?
Dear all, Please, look at the following code: attach(geyser) f1 <- kde2d(duration, waiting, n = 5) a <- 0 for (i in 1:5){ for (j in 1:5){ a <- a + f1$z[i,j] } } As far as I understood from Help kde2d returns matrix elements of which are values of joint probability mass function Pr(X=x,Y=y) therefore, sum of its elements should sum to 1. Which is not the case from my check. Where is
2011 Nov 24
2
Question on density values obtained from kde2d() from package MASS
Hello, I am a little bit confused regarding the density values obtained from the function kde2d() from the package MASS because the are not in the intervall [0,1] as I would expect them to be. Here is an example: x <- c(0.0036,0.0088,0.0042,0.0022,-0.0013,0.0007,0.0028,-0.0028,0.0019,0.0026,-0.0029,-0.0081,-0.0024,0.0090,0.0088,0.0038,0.0022,0.0068,0.0089,-0.0015,-0.0062,0.0066) y <-
2006 Jan 19
2
function kde2d
Good evening, I am Marta Colombo, student at Milan's Politecnico. Thank you very much for your kindness, this mailing list is really useful. I am using the function kde2d for two-dimensional kernel density estimation and I'd like to know something more about this kind of density estimator. In particular I'd like to know: what bandwidth is used ? Thank you in advance for your attention
2012 Nov 28
1
Plot 3d density
I want to create a 3d plot with densities. I use the function density to first create a 2d dimensional plot for specific x values, the function then creates the density and puts them into a y variable. Now I have a second set of x values and put it again into the density function and I get a second set of y variables and so on.... I want to put those sets into a 3d plot, I hope you know what I
2005 Jan 14
1
kde2d and borders
Hallo, I want to use kde2d to visualize data on a sphere given in spherical coordinates. Now the problem is, that "phi == 2*pi = 0", so in principal I have to connect (in a graphical view) the left and right border of my plot (and the bottom and top). Has anyone any idea how to do that ? Thanks, Manuel -- ------------------------------------- Manuel Metz Sternwarte der
2006 Jun 14
1
Estimate region of highest probabilty density
Estimate region of highest probabilty density Dear R-community I have data consisting of x and y. To each pair (x,y) a z value (weight) is assigned. With kde2d I can estimate the densities on a regular grid and based on this make a contour plot (not considering the z-values). According to an earlier post in the list I adjusted the kde2d to kde2d.weighted (see code below) to estimate the
2009 Mar 17
1
help with 3-D plot of kernel density estimates
Hi, I guess I have a naive question. I use kde2d function in a standard way to estimate kernel densities of x and y (x and y are vectors) and plot them using image(). f1=kde2d(x,y) image(f1) But what if I want to see kernel estimates of three variables, x, y and z (a vector) plotted together ? Something in which x<->y is plotted and colored according to the corresponding value of z ?
2007 Nov 26
2
2d Joint Density Plot
Hi all, I'm fairly new to R, so I'm still trying to feel out what is available to me. I would like to be able to plot joint density in a two dimensional plot where density is indicated by color or darkness gradients, like a 2d color coded topographic map. Ideally, the output would be something I could then plot other points or lines on. Currently, I'm calculating joint density with
2004 Dec 22
0
weighted kernel density estimation
Dear wizaRds, I use the MASS::kde2d function to estimate density of the two first principal components. I do that to have a graphic visualisation of a "group structure" in my dataset. So far, no problem. But i would like to estimate that density using weights according to the COS?? values that tells me if my observation is well represented on the factorial plan 1-2. I would like to
2013 Oct 15
1
plotting a marginal distribution on the plane behind a persp() plot
R'istas: I am trying to plot a marginal distribution on the plane behind a persp() plot. My existing code is: library(MASS) X <- mvrnorm(1000,mu=c(0,0),Sigma=matrix(c(1,0,0,1),2)) X.kde <- kde2d(X[,1],X[,2],n=25) # X.kde is list: $x 1*n, $y 1*n, $z n*n persp(X.kde,phi=30,theta=60,xlab="x_b",ylab="x_a",zlab="f") ->res Any suggestions are very
2003 Sep 17
0
Persp and color (again)
Hi guys, After all the discussion yesterday about persp and color, I decided to have a more closer look at demo(persp), and decided to write a function to generate 'topo-like' colours to plot perspectives (Thanks a lot to Uwe Ligges for his enlightning comments regarding the code in the demo). Here it goes, I believe that this function will be pretty useful to a lot of people:
2007 May 04
1
Partitioning a kde2d into equal probability areas
Hi, I'd like to partition a 2d probability density function into regions of equal probability. It is straightforward in the 1d case, like qnorm(seq(0,1,length=5)) but for 2d I'd need more constraints. Any suggestions for how to approach this? Is seems like a spatial sampling problem but I'm not sure where to look. Thanks for your time, Dave -- Dr. David Forrest drf at
2007 Jun 08
2
how to find how many modes in 2 dimensions case
Hi, Does anyone know how to count the number of modes in 2 dimensions using kde2d function? Thanks Pat
2003 Oct 22
1
2 D non-parametric density estimation
I have spatial data in 2 dimensions - say (x,y). The correlation between x and y is fairly substantial. My goal is to use a non-parametric approach to estimate the multivariate density describing the spatial locations. Ultimately, I would like to use this estimated density to determine the area associated with a 95% probability contour for the data. Given the strong correlation between x and
2003 Sep 01
0
Re: Plotting bivariate normal distributions.
You'll find that it is a lot easier to do it in R: # lets first simulate a bivariate normal sample library(MASS) bivn <- mvrnorm(1000, mu = c(0, 0), Sigma = matrix(c(1, .5, .5, 1), 2)) # now we do a kernel density estimate bivn.kde <- kde2d(bivn[,1], bivn[,2], n = 50) # now plot your results contour(bivn.kde) image(bivn.kde) persp(bivn.kde, phi = 45, theta = 30) # fancy contour with
2012 Apr 18
1
ggplot2 stat_density2d issue.
Hello, I'd be very grateful for help with some ggplot2's stat_density2d issues. First issue is with data limits. xlim() and ylim() doesn't seem to work; instead, estimates (and plotting) seems to be constrained to range(x), range(y) no matter what i do. The documentation says i can pass in kde2d's parameters to ... but pussing kde2d's "lims" parameter achieves