Displaying 20 results from an estimated 20000 matches similar to: "density of hist(freq = FALSE) inversely affected by data magnitude"
2009 Apr 22
1
converting histogram to barchart
Hi list,
After a lot of tweaking i have managed to create a histogram with an
overlaying density plot. The histogram shows a sample of birth weights
of babies and the density plot shows birth weights from a much larger
reference populaton. My data is divided in 0.1 Kg bins so in the code
below binweigh=0.1.
The trouble with the current graph is that it is not very clear since
the density plot
2009 Aug 19
1
Fw: Hist & kernel density estimates
For the hist estimate
>par(mex=1.3)
>dens<-density(q)
>options(scipen=4)
> ylim<-range(dens$y)
> h<-hist(q,breaks="scott",freq=FALSE,probability=TRUE,
+? right=FALSE,xlim=c(9000,16000),ylim=ylim,main="Histogram of q(scott)")
> lines(dens)
>box()
?
For the kernel estimate>options(scipen=4)
> d <- density(q, bw =
2010 Mar 30
1
hist.default()$density
Dear developers,
the current implementation of hist.default() calculates 'density' (and
'intensities') as
dens <- counts/(n*h)
where h has been calculated before as
h <- diff(fuzzybreaks)
which results in 'fuzzy' values for the density, see e.g.
> tmp <- hist(1:10,breaks=c(-2.5,2.5,7.5,12.5),plot=FALSE)
> print(tmp$density,digits=15)
[1]
2006 Apr 05
1
hist function: freq=FALSE for standardised histograms
Dear All,
I am a undergraduate using R for the first time. It seems like an excellent
program and one that I look forward to using a lot over the next few years,
but I have hit a very basic problem that I can't solve.
I want to produce a standardised histogram, i.e. one where the area under
the graph is equal to 1. I look at the manual for the histogram function and
find this:
freq:
2008 Jun 23
5
Need ideas on how to show spikes in my data and how to code it in R
Hi
I have recently been analyzing birthweight data from a clinic. The
data has obvious defects in that there is digit preference on certain
weights making them overrepresented. This shows as spikes in the
histogram on certain well rounded weights like 2, 2.5, 3, etc. I
would like to show this to government officials but can't figure out
how I should present the finding in an easy to
2005 Dec 13
8
superimpose density line over hist
Hi all,
I'm trying to superimpose a rchisq density line over a histogram with
something like:
hist(alnlength)
lines(density(rchisq(length(alnlength), 4)),col="red")
But the rchisq line won't appear anywhere,
Anyone knows what I am missing here?
Thanks in advance,
Albert.
2003 Jun 17
1
hist density...
Hi!
Do not understand following behavior.
> summary(test$dif)
Min. 1st Qu. Median Mean 3rd Qu. Max.
0.7389 0.9713 0.9850 0.9818 1.0000 1.0000
length(test$dif)
[1] 85879
tmp <- hist(test$dif,breaks=100,freq=FALSE)
The density on the Y axis in the plot are in the range 0-200.
Thought that the density should be in the range 0-1
(something like
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
2003 Mar 08
2
hist() basic question
Hi,
This is a very basic question, but I would like to undestand hist(). I
thought that the hist( , freq=FALSE) should provide the relative
frequencies (probabilities), and so they should sum 1, however:
set.seed(2)
ah <- hist(rnorm(100), freq=F)
sum(ah$intensities)
[1] 2
set.seed(2)
bh <- hist(rlnorm(100), freq=F)
sum(bh$intensities)
[1] 0.4999996
I'm getting similar figures with
1998 Jan 23
2
hist: rel.freqs
In R0.61,
In hist(), should the line
rel.freqs <- counts/(sum(x) * diff(breaks))
computing the relative frequencies or height of the rectangles
in a histogram not be
rel.freqs <- counts/(sum(counts) * diff(breaks))
instead, or do I misunderstand something?
Thanks,
Philippe
--
--------------------------------------------------------
Philippe Lambert Tel:
2010 Mar 13
2
Is this a bug (or a feature) in hist(x)$density ??
Hi all,
A friend send me a question on why does this:
x<-rpois(100,1)
sum( hist(x)$density )
Gives out "2"
I tried this:
sum( hist(x, freq =T)$density )
It didn't help.
Then he came back with the following insight:
# with breaks
b<-c(0,0.9,1:8)
sum(hist(x,breaks=b)$density) # Much more then 2
# but if we add weights according to the interval length
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 Aug 25
1
How to get back POSIXct format after calculating with hist() results
Hi,
I have a casting/formatting question on hist.POSIXt:
The histogram plot from POSIXct works perfect (with help of Prof. Ripley
-thanks!).
When processing the hist(plot=FALSE) output and then plotting the
results over the x-axis (bins) coming from hist(), I lose the date/time
labels, getting instead integers displayed.
Trying to cast the $breaks with as.POSIXct gives silly results with
2005 Nov 02
2
breaks in hist()
Dear listers,
A quick question about breaks in hist().
The histogram is highly screwed to the right, say, the range of the vector is [0, 2], but 95% of the value is squeezed in the interval (0.01, 0.2). My question is : how to set the breaks then make the histogram look even?
Thanks in advance,
Leaf
2006 Nov 10
3
unwarranted warning from hist.default (PR#9356)
> x = rnorm(100)
> b = seq(min(x) - 1, max(x) + 1, length = 11)
> b
[1] -3.4038769 -2.7451072 -2.0863375 -1.4275678 -0.7687980 -0.1100283
[7] 0.5487414 1.2075111 1.8662808 2.5250506 3.1838203
>
> invisible(hist(x, breaks = b, include.lowest = TRUE, plot = FALSE))
Warning message:
argument 'include.lowest' is not made use of in: hist.default(x,
breaks = b,
2009 Jul 26
2
problems hist() and density
Hello,
I have a problem with the hist() function and showing densities. The
densities sum to 50 and not to 1! I use R version 2.9.1 (2009-06-26) and
I load the seqinR library.
My data is the following vector:
[1] 0.1400000 0.2000000 0.2200000 0.2828283 0.1600000 0.1600000
0.3600000
[8] 0.1600000 0.2200000 0.2600000 0.2000000 0.3000000 0.2200000
0.2342342
[15] 0.1800000 0.2200000 0.1600000
2004 May 25
5
Histogram
Dear all,
I have a surprising problem with the representation of frequencies in a
histogram.
Consider, for example, the R code:
b<-rnorm(2000,3.5,0.3)
hist(b,freq=F)
When I plotted the histogram, I expected that values in the y-axis (the
probability) varied between 0 and 1. Instead, they varied within the
range 0-1.3.
Have you got any suggestion for obtaining a correct graph with
2003 Oct 02
2
hist (PR#4395)
It is not really a bug but a strange choice. When the option freq=F chosen, hist
should plot relative frequency. It plots proportional to relative frequency by
the factor of bin width. Is there a reason for this? A more normal choice seems
to be to have it independent of the bin width.
Yash Mittal
University of Arizona
----------------------------------------------------------------
This
2001 Oct 13
1
hist with relative frequency
Dear R People:
Here is yet another histogram question (yahq), please:
When I use the hist() command with
freq=F, I get density on the side.
I would really like to have relative frequency; that is,
Rf = density/(sum(density))
Is there a step that I'm leaving out, please?
thanks!
Sincerely,
Erin
hodgess at uhddx01.dt.uh.edu
2011 May 23
1
How is the relation between Frequency and Counts in hist/density defined?
Hi all,
I'm looking to add a "density" smoother on top of a hist when Freq=T.
In order to do this I can use the relation between count and density, but I
would like to know if there is a way for me to predict it upfront.
Here is an example:
set.seed(242)
z = rnorm(30)
hist_z <- hist(z)
hist_z$counts / hist_z$density # the relation is 15
# why is this 15 ??
# So I can now do: