Displaying 20 results from an estimated 3000 matches similar to: "detect if data is normal or skewed (without a boxplot)"
2008 Aug 09
2
how to interpret t.test output
# Hi all:
#I got a vector with fish lengths(mm)
# Can someone help me interpret the output of
# a t.test in plain english?
# Based on the t.test below I can say that
# I reject the null hypothesis because
# the p-value is smaller than the the significance
# level(alpha=0.05). What else can I conclude here?
Ho = 36 mm
Ha <> 36 mm
fishlength
2008 Jul 12
5
shapiro wilk normality test
Hi everybody,
somehow i dont get the shapiro wilk test for normality. i just can?t
find what the H0 is .
i tried :
shapiro.test(rnorm(5000))
Shapiro-Wilk normality test
data: rnorm(5000)
W = 0.9997, p-value = 0.6205
If normality is the H0, the test says it?s probably not normal, doesn
?t it ?
5000 is the biggest n allowed by the test...
are there any other test ? ( i know qqnorm
2007 Jul 18
1
Saving a dataset permanently in R
HI:
I'm still struggling with datasets, the more I read
about it the more confussed I get. This is the
scenario... In R console|Edit|Data Editor, I can find
all the datasets available with the different
packages, So to create a new dataset in the R console
I use the following commands to create an empty data
frame.
My_Dataset <- data.frame()
My_Dataset <- edit(My_dataset)
The problem is
2011 May 27
1
Normality test
Dear Sir,
I am writing to inquire about normality test given in nortest package. I
have a random data set consisting of 300 samples. I am curious about which
normality test in R would give me precise measurement, whether data sample
is following normal distribution. As p value in each test is different in
each test, if you could help me identifying a suitable test in R for this
medium size of
2012 Dec 17
5
save to file
Hi,
What's the equivalent of "Save to File" from the R console File menu on an R routine? Just trying
to capture the whole R console into a text file when my code fails.
Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA
http://www.fws.gov/redbluff/rbdd_jsmp.aspx
[[alternative HTML version deleted]]
2004 Feb 04
5
nortest package
Hi,
I'm a newbie and i am unable to use lillie.test in nortest
I have a message: "Couldn't find function "lillie.test"
I am under windows2000 with R1.8.1
nortest is listed with .packages(TRUE)
How to do to use lillie.test function?
Laurent Houdusse
Analyste Programmeur
2006 May 21
3
normality testing with nortest
I don't know from the nortest package, but it should ***always***
be the case that you test hypotheses
H_0: The data have a normal distribution.
vs.
H_a: The data do not have a normal distribution.
So if you get a p-value < 0.05 you can say that
***there is evidence***
(at the 0.05 significance level) that the data are not from a
normal distribution.
If the nortest package does
2006 Jun 14
1
Bug in nortest cvm.test package (PR#8980)
I believe there to be a bug in the cvm.test module of the nortest
package authored by Juergen Gross. I do not know how to contact the
author directly.
I've been running some normality tests using the nortest package. For
some of my datasets the Cramer-von Mises normality test generates an
extremely high probability (e.g., 1.637e+31) and indicates normality
when the other tests do
2011 Apr 03
1
another question on shapefiles and geom_point in ggplot2
Manuel:
I changed your variable names from x to 'long' and y to 'lat' on the
riqueza_out.csv file.
The code below should do what you want. Also, since the legend title is kind of
long, I broke it
down into three lines so you can see more plot area. I am cc'ing the other
groups so more people
use it if needed.
library(rgdal)
library(ggplot2)
library(sp)
library(maptools)
2008 Mar 22
2
counting values on one colum only
Hi all:
Can someone help me count the
number of rows with values in
colum "a" only. assume the name
of my dataframe is "weekly"
I was trying
i<- nrows(weekly$a)
i
but returns 7 when it should
be 4. Thanks
a b c d
27.000
27.000
1.569 0.013 160.000 27.000
1.632 0.013 146.000 27.000
1.830 0.015 70.000 27.000
2.475 0.019
2005 Nov 17
1
(no subject)
Hi there,
I am trying to perform different normality tests in R. I have no problem
when I use Shapiro.test( ). However, when I try to use any normality
tests from the Nortest package, I kept getting this error " Error in
read.table(source, header = T, fill = T) :
'file' must be a character string or connection". I have no idea
why because there was no problem with
2006 Jun 13
1
Cramer-von Mises normality test
Hi, this is my first help request so please bear with me.
I've been running some normality tests using the nortest package. For
some of my datasets the Cramer-von Mises normality test generates an
extremely high probability (e.g., 1.637e+31) and indicates normality
when the other tests do not. Is there something I'm misunderstanding
or potentially a bug in the code?
Below are the
2009 Jan 21
4
seq()
HI:
Could someone help me with the seq function? I have a range of values starting from 1 to 52 but I want seq to start at 27 by=2, but when it reaches 51 start with with number 1 to 25. is this possible. I can do the basics of seq() but I can't figure how to do this one. This is how I want my sequence to look like:
27 29 31 33 35 37 ............51 1 3 5 7 9 11 13 ...........25
Felipe D.
2010 Sep 02
1
Error: could not find function "ad.test"
Hi,
I'm trying to run an anderson-darling test for normality on a given variable
'Y':
ad.test(Y)
I think I need the 'nortest' package, but since it does not appear in any of
the Ubuntu repositories for 2.10.1, I am wondering if it goes by the name of
something else now?
Thanks
--
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2010 Jul 24
2
How to generate a sequence of dates without hardcoding the year
Hi:
I have a dataframe named 'spring' and I am trying to add a new variable named
'IdDate'
This line of code works fine:
spring$idDate <- seq(as.Date("2008-07-01"),as.Date("2009-06-30"),by="week")
But I don't want to hardcode the year because it will be used again the
following year
Is it possible to just generate dates with the month and
2008 Oct 11
6
Sweave-LaTEX question
Hi:
I am working on a publication and I have heard about LaTEX but I haven't actually tried to learn about it until today. I've found a few examples but I can't actually make them work properly. I have a couple of questions:
Does LATEX have to be installed on your computer? How does the xtable package and Sweave work together? How can I make the code below create a table as pdf file?
2010 Oct 01
3
gridExtra question
?
Hi:
I get?a couple of warnings? when trying to download gridExtra:
install.packages("gridExtra",repos=http://R-Forge.R-project.org)
?Warning: unable to access index for repository
http://R-Forge.R-project.org/bin/windows/contrib/2.10
Warning message:
In getDependencies(pkgs, dependencies, available, lib) :
? package ?gridextra? is not available
I would like to download the binary
2008 Mar 16
2
How to loop through all the columns in dataframe
Hi:
Can anyone advice me on how to loop and perform a
calculation through all the columns.
here's my data
xd<-
c(2.2024,2.4216,1.4672,1.4817,1.4957,1.4431,1.5676)
pd<-
c(0.017046,0.018504,0.012157,0.012253,0.012348,0.011997,0.012825)
td<- c(160524,163565,143973,111956,89677,95269,81558)
mydf<-data.frame(xd,pd,td)
trans<-t(mydf)
trans
I have these values that I need to
2006 Aug 23
5
negatively skewed data; reflecting
Hi,
This problem may be very easy, but I can't think of how to do it. I have constructed histograms of various variables in my dataset. Some of them are negatively skewed, and hence need data transformations applied. I know that you first need to reflect the negatively skewed data and then apply another transformation such as log, square root etc to bring it towards normailty. How is it
2010 Nov 29
2
drop levels problem
Hi all:
I am having trouble dropping levels, got a few hints online?without success.
Please consider the dataset below:
?I was under the inpression that subset(......drop=TRUE) would work but it
doesn't
library(ggplot2)
??? library(hmisc)
x <- structure(list(first = c(38.2086, 43.1768, 43.146, 41.8044, 42.4232,
46.3646, 38.0813, 40.0745, 40.4889, 38.6246, 40.2826, 41.6056,
34.5353,