Displaying 20 results from an estimated 10000 matches similar to: "Quantil-quantile plot help"
2002 Sep 30
5
Chi-Square Distribution Plots
Dear list
I have a vector of values that allegedly have a chi-squared distribution. I
want to create a plot that shows the values I have obtained, and the
chi-squared distribution curve for the specified number of degrees of freedom
to show what should have been obtained.
At the moment I am plotting the values I have obtained as a histogram and
somehow want to put on to this plot the
2002 Oct 14
2
Vector of quantiles
I have a quick question which is very simple but I seem to have a mental
block!
I'm using the pchisq function to specify a Chi Squared distribution with 9 df
which I'm then going to use in the Kolmogorov-Smirnov Test to test some
simulated values.
so simply: pchisq(q, df=9)
I know that q is the vector of quantiles but could anybody tell me what
exactly this vector needs to contain?
2005 Apr 28
3
have to point it out again: a distribution question
Stock returns and other financial data have often found to be heavy-tailed.
Even Cauchy distributions (without even a first absolute moment) have been
entertained as models.
Your qq function subtracts numbers on the scale of a normal (0,1)
distribution from the input data. When the input data are scaled so that
they are insignificant compared to 1, say, then you get essentially the
2017 Jun 16
0
"reverse" quantile function
It would depend on which one of the 9 quantile definitions you are using. The discontinuous ones aren't invertible, and the continuous ones won't be either, if there are ties in the data.
This said, it should just be a matter of setting up the inverse of a piecewise linear function. To set ideas, try
x <- rnorm(5)
curve(quantile(x,p), xname="p")
The breakpoints for the
2017 Jun 15
2
"reverse" quantile function
David,
thanks for the response. In your response the quantile function (if I see correctly) runs on the columns versus I need to run it on the rows, which is an easy fix, but that is not exactly what I had in mind... essentially we can remove t() from my original code to make "res" look like this:
res<-apply(z, 1, quantile, probs=c(0.3))
but after all maybe I did not explain
2007 Nov 30
2
Quantiles and QQ plots
I have 20 variables:
5,9,6,1,5,9,7,4,5,6,3,2,4,8,9,6,1,8,4,8
How do I calculate the corresponding quantiles from a normal distribution
with the same mean and variance as the sample?
Also, how do I draw a QQ plot of the data?
Thanks for any help!
--
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2013 Sep 10
1
[PATCH] show vector length in summary()
(summary.default): show the vector length in addition to quantiles
diff -u -i -p -F '^(def' -b -w -B /home/sds/src/R-3.0.1/src/library/base/R/summary.R.old /home/sds/src/R-3.0.1/src/library/base/R/summary.R
--- /home/sds/src/R-3.0.1/src/library/base/R/summary.R.old 2013-03-05 18:02:33.000000000 -0500
+++ /home/sds/src/R-3.0.1/src/library/base/R/summary.R 2013-09-10 10:19:02.682946339
2002 May 14
2
quantile() and boxplot.stats()
Hello,
I faced something I can't understand. When I use boxplot.stats(1:10) and
quantiles(1:10) the results are different for 25% and 75%:
> boxplot.stats(1:10)
$stats
[1] 1.0 3.0 5.5 8.0 10.0
> quantile(1:10)
0% 25% 50% 75% 100%
1.00 3.25 5.50 7.75 10.00
Actually, I expected the value 3 for 25% and 8 for 75% as results of
quantile(1:10). Can you please explain me
2010 Aug 24
3
odd behavior of "summary" function
Hello All,
Using the standard "summary" function in 'R', I ran across some odd
behavior that I cannot understand. Easy to reproduce:
Typing:
summary(c(6,207936))
Yields::
Min. *1st Qu. Median Mean 3rd Qu. Max.*
6 *51990 104000 104000 156000 207900*
None of these values are correct except for the minimum. If I perform
"quantile(c(6,
2011 Mar 24
3
tapply with specific quantile value
All -
I have an example data frame
x l.c.1
43.38812035 085
47.55710661 085
47.55710661 085
51.99211429 085
51.99211429 095
54.78449958 095
54.78449958 095
56.70201864 095
56.70201864 105
59.66361903 105
61.69573564 105
61.69573564 105
63.77469479 115
64.83191994 115
64.83191994 115
66.98222118 115
66.98222118 125
66.98222118 125
66.98222118 125
66.98222118 125
and I'd like to get the 3rd
2006 Jul 01
1
noncentral F-distributed random numbers (PR#9055)
Full_Name: Long Qu
Version: 2.3.1
OS: Windows XP
Submission from: (NULL) (64.113.93.235)
The QQ-plot of two versions of simulating noncentral F-distributed random
numbers has quite different scales:
> qqplot(rf(1000,2,15,3),qf(runif(1000),2,15,3))
The rf() function reads:
> rf
function (n, df1, df2, ncp = 0)
{
if (ncp == 0)
.Internal(rf(n, df1, df2))
else rchisq(n, df1,
2002 Dec 08
3
strange QQ-Plot
Hi,
i am working on a data set with EDA. That includes QQ-Plots of
residuals vs expected normal distribution.
What puzzles me is that the range of ordinate and abscissae is
so different: while the theoretical quantiles range from [-2, 2]
the sample quantiles on the ordinate do extent from [-20, 50].
Quite obviously some kind of transformation is done.
Although i intensively RTFM i could not
2009 Dec 13
2
A random number from any distribution?
Hello,
I have some data, and I want to generate random numbers following the distribution of this data (in other words, to generate a synthetic data set sharing the same stats as a given data set). Reading an old thread I found the following text:
>If you can compute the quantile function of the distribution (i.e., the
>inverse of the integral of the pdf), then you can use the
2011 Mar 08
1
R Commander QQ Plot with triangular distribution
I am attempting to use the R Commander Graphs Quantile-Comparison
functionality on a dataset, to compare with a triangular distribution.
I have the package triangle. My question is on the syntax of how
to specify the parameters of the theoretical distribution in the
Parameters field of the dialog box. For example, the theoretical
distribution has min of 3000, max of 5000, mode of 4000. When
2017 Jul 23
0
cannot use package RcmdrPlugin.plotByGroup
On 2017-7-23 20:41, Fox, John wrote:> ...
> The Rcmdr uses the qqPlot() function in the car package. In the next
> version of the car package, qqPlot() will be able to plot by groups,
> and when that happens, I'll incorporate the feature in the Rcmdr.
>
> More generally, however, if you learn to write R commands you'll be
> able to make customized plots. It would be
2013 Apr 05
1
mixed formatting of integer and numeric (e. g., by summary.default())
Hello, eveRybody,
I've been trying to find the origin for the following
formatting-"inconsistency":
E. g., look at the number of digits in summary.defaults()'s output when
NAs occur: in my example below the number of NA's is displayed as an
integer, the rest as numeric (floating point numbers):
> summary.default( c( 1:2, NA))
Min. 1st Qu. Median Mean 3rd Qu.
2006 Oct 25
1
Drawing a reference line for a qqplot with reference to Weibull distribution
Hi,
I'm trying to create a qqplot with reference to a Weibull distribution
including a reference line. This is my current code:
lights.data <- scan("lights.dat")
#Generate Weibull quantiles
prob.grid <- ppoints(length(lights.data))
prob.quant <- qweibull(prob.grid , 1.5,4)
#Draw QQ plot
qqplot(prob.quant,lights.data)
#add red reference line
qqline(lights.data,col = 2)
2005 Oct 04
6
boxplot statistics
I have read and reread the boxplot and the boxplot stats page, and I
still cannot understand how and what boxplot shows. I realize that
this might be due to me not knowing enough statistics, but anyway...
First, how does boxplot determine the size of the box? And is the line
inside the box the mean or the median (or something completely
different?) And how does it determine how long out the
2010 Nov 09
1
the formula of quantile regression for panel data, which is correct?
Hi,everyone
I have some trouble in understanding the formula.
http://r.789695.n4.nabble.com/file/n3033305/%E6%9C%AA%E5%91%BD%E5%90%8D.jpg
http://r.789695.n4.nabble.com/file/n3033305/%E6%9C%AA%E5%91%BD%E5%90%8D1.jpg
which is correct?
best wish.
thanks
--
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2004 Oct 23
4
Plotting Bivariate Normal Data
Dear list
I have a vector of values that allegedly have a bivariate normal distribution.
I want to create a plot that shows the values I have obtained, and the
bivariate normal distribution curve for the data.
Is there a way of doing this in R?
Many thanks for your help,
Sarah.
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