Displaying 20 results from an estimated 50000 matches similar to: "density at particular values"
2010 May 10
2
Warning message
Hello,
I want to draw a histogram of the mean of sample observations drawn from multivariate t distribution. I am getting the following error corresponding to the code I used. Though I am getting the graph, but I am curious to know the warning message.
Warning messages:
1: In if (freq) x$counts else { :
the condition has length > 1 and only the first element will be used
2: In if (!freq)
2011 Jun 27
1
Kernel Density Estimation at manually specified points
Hello,
my name is Carsten. This ist my first post to R-help mailing list.
I estimate densities with the function "density" out of the package
"stats".
A simplified example:
#generation of test data
n=10
z = rnorm(n)
#density estimation
f=density(z,kernel="epanechnikov",n=n)
#evaluation
print(f$y[5])
Here I can only evaluate the estimation at given
2000 Nov 17
2
hist() and density
There were some questions about hist() a couple of days ago which
triggered this post. My question/suggestion is about the y-axis in hist.
There are reasons to prefer making the y-axis density=relative
frequency/bin width. One reason is that the height of the plot does not
depend on the bin width; another is that if your histogram is in density
then you can easily superimpose a smooth theoretical
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
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
2010 Feb 15
4
density estimates for fixed points
Problem:
Based on a n x 2 data matrix i want a kernel estimate of the bivariate
density. However, i also wish to specify wich points the density should be
calculated at.
I can offcourse just write the full kernel density estimate as a R-code, but
surely there must already exist some package for this operation?
The package density(), seems to create a new matrix (depending on n), where
the
2010 Jul 20
2
Constrain density to 0 at 0?
I'm plotting some trip length frequencies using the following code:
plot( density(zTestData$Distance, weights=zTestData$Actual),
xlim=c(0,10),
main="Test TLFD",
xlab="Distance",
col=6 )
lines(density(zTestData$Distance, weights=zTestData$FlatWeight), col=2)
lines(density(zTestData$Distance, weights=zTestData$BrdWeight ), col=3)
which works fine except the
2006 Aug 30
2
density() with from, to or cut and comparrison of density()
Hi
the function density() does normally integrate to one - I've checked it
and it works and I also read the previous threads.
But I realised that it does not integrate to one if I use from, to or cut.
My scenario: I simulated densities of a plants originating from an sseed
source at distance zero. Therefore the density of the plants will be
highest close to zero. Is there anything I can do
2009 Nov 05
5
Density estimate with bounds
Dear R users,
I would like to show the estimated density of a (0, 1) uniformly distributed
random variable. The density curve, however, goes beyond 0 and 1 because of the
kernel smoothing.
Example:
x = runif(10000)
plot(density(x))
Is there a way to estimate the density curve strictly within (0, 1) and still
use some sort of smoothing?
Any help would be greatly appreciated.
Best regards,
2008 Sep 29
2
density estimate
Hi,
I have a vector or random variables and I'm estimating the density using
"bkde" function in the KernSmooth package. The out put contains two vectors
(x and y), and the R documentation calls y as the density estimates, but my
y-values are not exact density etstimates (since these are numbers larger
than 1)! what is y here? Is it possible to get the true estimated density at
each
2016 Nov 13
1
dgamma density values in extreme point
Dear R-Devel group,
My name is Alexey, a data scientist from Moscow, currently working for
Align Technology Inc.
We have recently had a discussion of the results that the dgamma
function (stats) returns for an extreme point (x == 0).
<dgamma(0,1,1,log = FALSE)
[1] 1
and
<dgamma(0,0.5,1,log = FALSE)
[1] Inf
Density appears to be defined in point zero for the distribution with
the
2003 Sep 24
3
density() integrates to 1?
Visual inspection of the plot of a density() function vs a normal with
the same mean and variance suggests the area under the density curve is
bigger than under the normal curve. The two curves are very close over
most of the domain. Assuming the normal curve does integrate to 1, this
implies the area under density() is > 1.
Is there any assurance that the density kernel smoother produces
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 <-
2004 Nov 13
3
density estimation: compute sum(value * probability) for given distribution
Dear R users,
This is a KDE beginner's question.
I have this distribution:
> length(cap)
[1] 200
> summary(cap)
Min. 1st Qu. Median Mean 3rd Qu. Max.
459.9 802.3 991.6 1066.0 1242.0 2382.0
I need to compute the sum of the values times their probability of
occurence.
The graph is fine,
den <- density(cap, from=min(cap),
to=max(cap), give.Rkern=F)
2010 Jun 02
1
code for power and suffix for x,y labels in plot( ).
Hi
I was trying to have a graph whose axes are X axis: m, Y axis: var[X ((a,b) in suffix, and (n,d) in the power)].
X ((a,b) in suffix, and (n,d) in the power)- X^(n,d) _ (a,b).
Actually I require many plots involving different values of a,b,n,d, so need to keep this complicated notation.
The expression() didn't work out for this case. Can anyone help me out.
Thanks, in advance.
2011 Jun 09
1
histogram - density on y axis and restriction to interval [0, 1]
Hello,
To indicate probability densities instead of counts on a histogram, I
specify freq = FALSE.
However, I expect that summing all top y coordinates over all the
intervals of the histogram will provide 1.
1)
v <- c(0.2885, 0.2988, 0.3139, 0.2615, 0.3179, 0.3163, 0.2583, 0.3052,
0.2527, 0.3147, 0.3235, 0.2408, 0.2480, 0.3108, 0.3577, 0.2829, 0.2694,
0.3275, 0.3314, 0.2639, 0.3076,
2011 Jun 25
2
Multivariate normal density in C for R
Does anyone know of a package that uses C code to calculate a multivariate
normal density?
My goal is to find a faster way to calculate MVN densities and avoid R loops
or apply functions, such as when X and mu are N x K matrices, as opposed to
vectors, and in this particular case, speed really matters. I would like to
be able to use .C or .Call to pass X, mu, Sigma, and N to a C program and
have
2002 Nov 14
1
evaluating density objects
An object of class `density' has `x' and `y' components, which are what you
need to do the plot. Just bind them into a matrix and use write() to write
to a file.
HTH,
Andy
-----Original Message-----
From: Hinnerk Boriss [mailto:boriss at izbi.uni-leipzig.de]
Sent: Thursday, November 14, 2002 7:12 AM
To: R-help at stat.math.ethz.ch
Subject: [R] evaluating density objects
Hi!
Is
2009 Mar 01
1
projecting GIS coordinates for analysis with spatstat package
I am working on creating an R package for doing fire department analysis and
am trying to create a function that can display emergency incident
densities. The following code sort of does the trick, but I need a display
that shows the number of incidents per square mile. I believe the code
below shows incidents per square unit (in this case, degrees lat/long).
To solve this problem, I believe
2009 Jun 04
1
hist returning density larger than 1
The following code is giving me problems. I want to export densities
of a distribution to a csv file. At the bottom of the code I use the
hist function to generate the densities. But hist is returning values
greater than 1. I don't understand, why. Any help you can supply is
greatly appreciated.
# Set word path
dir<-"~/Research/MR Distribution Analysis/"
setwd(dir)