Displaying 20 results from an estimated 20000 matches similar to: "plotting density for truncated distribution"
2008 Aug 29
3
Density estimates in modelling framework
Hi all,
Do any packages implement density estimation in a modelling framework?
I want to be able to do something like:
dmodel <- density(~ a + b, data = mydata)
predict(dmodel, newdata)
This isn't how sm or KernSmooth or base density estimation works. Are
there other packages that do density estimation? Or is there some
reason that this is a bad idea.
Hadley
--
http://had.co.nz/
2001 May 10
3
lookup function for density(...) objects
Hi folks:
Is there a lookup function that returns the variate given the cumulative
probability for an object returned by the density(...) function?
> mydata _ as.vector(mymatrix)
> mydata.density _ density(mydata)
> mydata.p80 _ lookup(mydata.density, p=0.8) # is there any function to
accomplish this task?
Thanks.
Rajiv.
--------
Rajiv Prasad, Postdoctoral Research Associate,
2006 Aug 23
5
two density curves in one plot?
Hello,
I was wondering if I can plot two curves I get from "density(data)" into
one plot. I want to compare both.
With the following commad, I just get one curve plotted:
plot( density(mydata) )
Sorry for this stupid question but I could not find a solution until now...
Antje
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)
2009 Dec 04
1
length of a density curve (or any curve)
Hello R users,
When I type
d <- density(MyData$x)
I obtain a density object I can plot,
But I wonder if there is a way to easily compute the length of the
density curve ?
( I imagine I could compute the distances between the 512 equally
spaced points using their x and y, but does it exist a smarter way ?)
Regards,
SW
2009 Apr 10
2
Stacked density plots
Hello R-community,
I want to generate stacked density plots in lattice. My data consist of a numeric variable ('pid') that is measured in different individuals ('id'), which can be divided in two types ('type') and the measurements were repeated a different time points ('day').
I read in the Lattice book that this can be done using the 'flowViz'
2010 Nov 11
3
overlap histogram and density
Hi,
Does anybody encounter the same problem when we overlap histogram and density
that the density line seem to shift to the right a little bit?
If you do have the same problem, what should we do to correct that?
Thank you.
par(mar=c(4,4,2,1.2),oma=c(0,0,0,0))
hist(datobs,prob=TRUE, main ="Volume of a catchment from four
2008 Feb 27
1
ggplot2 boxplot confusion
Ultimately my aim is to get a plot of density faceted by 2 factors with a
horizontal boxplot overlaid on each density plot in the grid to indicate
summary stats. So I've been experimenting with creating boxplots and density
plots. Here's some representative data.
series = c('C2','C4','C8','C10','C15','C20')
ids =
2009 Aug 22
1
plotting the graph of density with an unknown distribution
How can I plot the graph of a density of a sample with an unknown distribution? I can provide any sample size which is required. I want to have a smooth density graph of my data.
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2004 Nov 26
2
hist and truehist
Hello!
Up to now I have been using hist() to display the distributions.
Howevere, I noteiced strange numbers on y (vertical) axis, if I used
probability = T or freq = F option. I thought it is a bug and launched
the R-bug system and found some posts on that matter. Brian Ripley
responded to one, that one should look at truehist() for that. Ok I can
use truehist() if I want to see the ratios
2006 Feb 15
1
using kernel density estimates to infer mode of distribution
Hello...
Is it possible to use "density" or another kernel density estimator to
identify the mode of a distribution? When I use 'density', the resulting
density plot of my data is much cleaner than the original noisy histogram,
and I can clearly see the signal that I am interested in. E.g., suppose my
data is actually drawn from two or more normal (or other)
2011 Jan 02
1
How to compute the density of a variable that follows a proportional error distribution
Hello,
I am trying to compute the density of a variable k that is either (1)
Normally distributed; (2) Log-Normally distributed; or (3) follows
proportional error distribution. I tried to search R-help and the answer for
normal distribution was easy to find (please see 1c). I am not sure if my
formula for dlnorm is correct (please see 2c below)? I really don't know
what function to use for the
2005 May 04
1
Questions about the intersection area under two kernel densities
Hi there,
I am working on a project which needs the value of the interaction area under two distributions( eatimated by kernel density estimators).
For example:
x<-rnorm(100,0,1)
y<-rnorm(100,0.2,1)
density(x) # This produces the summary of dependent variable and independent variable.
How can I get the individual values of variables and reform a curve to calculate the area under
2004 Mar 17
3
Persp plotting of kernel density estimate.
Dear All,
I am trying to visualize the surface of a bivariate kernel density
estimate.
I have a vector of bivariate observations(x,y), and a function which
computes the kernel density estimate z corresponding to each
observation.
I cannot generate the (x,y) data in the ascending order needed by
persp(x,y,z).
I was wondering whether there is an R version of the S function interp.
Would anybody
2010 Feb 09
2
Comparing means and trends in short time-series
Dear R-list,
I have a statistical problem with the comparison of short time-series,
representing densities of fish in different streams. For each stream (6 in
total, here below showed only part of the dataset) I have 8 years of density
data, as follows:
year density stream
1 2000 0.51 stream1
2 2001 0.87 stream1
3 2002 0.68 stream1
4 2003 0.56 stream1
5 2004 0.50 stream1
6
2003 Sep 09
1
Newbie question about plotting density objects
Dear List,
I have an array of 6400 x 56 elements. I want to calculate the density function for each column and plot all 56 density functions in one plot.
I have tried several procedures, but they all failed.
What can I do?
TIA
Christian
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2003 Apr 09
3
plotting the lognormal density curve
I am trying to plot a lognormal density curve on top of an existing
histogram. Can anybody suggest a simple way to do this? Even if someone
could just explain how to plot a regular normal density curve on top of an
existing histogram, it would be a big help.
Also, is there some way to search through the R-help archives other than
simple browsing?
Thank you so much. Your help and time is greatly
2010 Jun 25
1
what "density" is plotting ?
Hi everyone,
I am confused regarding the function "density".
suppose that there is a sample x of 100 data points, and plot(density(x))
gives it's pdf ?
or it's more like histogram only ?
thanks for any answering
Carrie
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2010 Jan 01
2
How to calculate density function of Bivariate binomial distribution
Am trying to do some study on bivariate binomial distribution. Anyone knows
if there is package in R that I can use to calculate the density function of
bivariate binomial distribution and to generate random samples of it.
Thanks,
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Sent from the R help
2008 Oct 07
3
Fitting weibull, exponential and lognormal distributions to left-truncated data.
Dear All,
I have two questions regarding distribution fitting.
I have several datasets, all left-truncated at x=1, that I am attempting
to fit distributions to (lognormal, weibull and exponential). I had
been using fitdistr in the MASS package as follows:
fitdistr<-(x,"weibull")
However, this does not take into consideration the truncation at x=1. I
read another posting in this