Displaying 20 results from an estimated 1000 matches similar to: "significantly different from one (not zero) using lm"
2013 May 03
1
R package for bootstrapping (comparing two quadratic regression models)
Hello ,
I want to compare two quadratic regression models with non-parametric
bootstrap.
However, I do not know which R package can serve the purpose,
such as boot, rms, or bootstrap, DeltaR.
Please kindly advise and thank you.
Elaine
The two quadratic regression models are
y1=a1x^2+b1x+c1
y1= observed migration distance of butterflies()
y2=a2x^2+b2x+c2
y2= predicted migration distance of
2012 Dec 16
3
averaging X of specific Y (latitude)
Hello
I have a table describing butterfly range traits.
It is composed of three columns as below
Species name range size (X) latitude of range midpoint (Y)
There are 11 kinds of butterflies.
Each has its range size, and the latitude of each range midpoint ranges
from 9 to 19.
I would like to have the average range size of every degree of latitude.
For example, the average range
2012 Dec 16
1
average X value of specific Y
Hello
I have a table describing butterfly range traits.
It is composed of three columns as below
Species name range size (X) latitude of range midpoint (Y)
There are 11 kinds of butterflies.
Each has its range size, and the latitude of each range midpoint ranges
from 9 to 19.
I would like to have the average range size of every degree of latitude.
For example, the average range
2010 Oct 12
1
delta AIC for models with 2 variables using MuMIn
Dear List,
I want to ask a AIC question based on package library(MuMIn)
The relative importance of 16 explanatory variables
are assessed using delta AIC in a generalized linear model.
Please kindly advise if it is possible to show models
with any two only certain variables.
Thank you.
Elaine
I asked a similar question and got a great help for models
with only one variable as below.
2010 Aug 17
2
AIC in MuMIn
Hello,
I am using package MuMIn to calculate AIC for a full model with 10
explanatory variables.
Thanks in advance in sharing your experience.
Q1
In the AIC list of all models, each model is differentiated by model number.
Please kindly advise if it is possible to
find the corresponding explanatory variable(s) for the model number.
Q2 error message
I tried to display sub-model with only
2007 Oct 05
3
R-2.6.0 package check problems
Hello
One of my packages, untb_1.3-2, passes R CMD check under
MacOSX (and apparently the systems used in the package check
summary page on CRAN) but fails with the following message on
R-2.6.0.tgz compiled last night on my (home) linux box. I hasten
to add that I have never seen this error before on home-compiled
pre-releases of R-2.6.0.
Can anyone help me understand what is going on?
2008 Aug 11
1
Simple lme/lmer random effects questions
Hello,
I have two very rudimentary questions regarding the random effects terms
in the lme and lmer functions. I apologize if this also partly strays
into a general statistics question, but I'm a bit new to this all. So
hopefully it'll be a quick problem to sort out...
Here is my experimental setup: I raised butterflies in 5 different
testing chambers all set to different
2014 Feb 05
1
ldb segment fault. Problem on joining as a DC member.
Dear All,
Need some help as I was trying to follow the guide below.
https://wiki.samba.org/index.php/Samba4/HOWTO/Join_a_domain_as_a_DC
Until the steps of
ldbsearch -H /usr/local/samba/private/sam.ldb '(invocationid=*)'
--cross-ncs objectguid
and my ldbsearch reply with such a result.
ldb: unable to dlopen /usr/lib64/samba/ldb/acl.so :
/usr/lib64/ldb/libreplace.so: version
2010 Jul 30
4
transpose of complex matrices in R
Hello everybody
When one is working with complex matrices, "transpose" very nearly
always means
*Hermitian* transpose, that is, A[i,j] <- Conj(A[j,i]).
One often writes A^* for the Hermitian transpose.
I have only once seen a "real-life" case
where transposition does not occur simultaneously with complex conjugation.
And I'm not 100% sure that that wasn't a
2005 Feb 01
1
mdct.c optimization
I took function mdct_butterfly_8 and write out transformation matrix. Then I rewrote this matrix into sequence of additions and substractions (see attachement). As I suspected I got the same as in the original code but I swaped some rows to get little higher speed. I hope I'll do the same with 16 point butterfly function combined with 8 point butterflies in a month. Who still believe that this
2009 May 26
2
Problem with fractional seconds
Dear List,
I am having problems converting a file with fractional seconds to class POSIXct. I have set my options to include digits.secs and my format to just time, but my output is the current date with my time lacking the fractions of a second. For example:
options(digits.secs=3)
t<-c("06:00:00.100","06:00:01.231")
myt<-as.POSIXct(t,format="%H:%M:%S")
2013 May 03
0
significant test of two quadratic regression models (lm)
Hello,
I am work with two quadratic regression models
y=ax^2+bx+c with the function of lm.
y1= observed migration distance of butterflies(y1=a1x^2+b1x+c1)
y2= predicted migration distance of butterflies (based on body mass)
(y2=a2x^2+b2x+c2)
x= body mass of butterflies
Now I would like to check the two regression model differ
by testing if the coeffients (a, b, c) of the y1 and the y2
2007 Jul 07
1
calculating p-values of columns in a dataframe
I have a dataframe ("mydf") that contains "differences of means".
I wish to test whether these differences are significantly different from zero.
Below, I calculate the t-statistic for each column.
What is a "good" method to calculate/look-up the p-value for each column?
mydf=data.frame(a=c(1,-22,3,-4),b=c(5,-6,-7,9))
mymean=mean(mydf)
mysd=sd(mydf)
2013 Sep 27
3
Compare species presence and absence between sites
Dear List,
I want to compare the presence and absence of bird species based on the
sites in a matrix.
The matrix has 5 rows for Island A, B, C, D, and E.
It has 100 columns for bird species D001-D100.
In each cell of the matrix,
the presence-absence of bird species will be recorded as 1 or 0.
(For example, if species D001 is found on Island D,
the matrix cell of species D001 and Island D
2013 Apr 17
1
failed to download vegan
Hello,
This is Elaine.
I am using R 3.0 to download package vegan but failed.
The warning message is
package ‘vegan’ successfully unpacked and MD5 sums checked
Warning: unable to move temporary installation
‘C:\Users\elaine\Documents\R\win-library\3.0\file16c82da53b1b\vegan’ to
‘C:\Users\elaine\Documents\R\win-library\3.0\vegan’
I cannot find the folder \file16c82da53b1b\ below
2013 Sep 20
3
search species with all absence in a presence-absence matrix
Dear list
I have a matrix composed of islandID as rows and speciesID as columns.
IslandID: Island A, B, C….O (15 islands in total)
SpeciesID: D0001, D0002, D0003….D0100 (100 species in total)
The cell of the matrix describes presence (1) or absence (0) of the species
in an island.
Now I would like to search the species with absence (0)
in all the islands (Island A to Island O.)
2013 Mar 18
1
try/tryCatch
Hi All,
I have tried every fix on my try or tryCatch that I have found on the
internet, but so far have not been able to get my R code to continue with
the "for loop" after the lmer model results in an error.
Here is two attemps of my code, the input is a 3D array file, but really
any function would do....
metatrialstry<-function(mydata){
a<-matrix(data=NA, nrow=dim(mydata)[3],
2012 Sep 24
3
boxplot of different colors
Hello,
I am making a boxplot of 13 boxes.
I tried to color the box using 13 colors but failed.
Only red and brown were displayed.
Green, blue, and grey disappeared.
Please kindly advise modification after checking the code below.
Thank you in advance.
Elaine
R code
# data input
dataN
<-read.csv("H:/a_mig_distance_B_NB/R_data/Mig_bird_586_20120925.csv",header=T,
row.names=1)
2012 Sep 28
2
changing outlier shapes of boxplots using lattice
Hello
This is Elaine.
I am using package lattice to generate boxplots.
Using Richard's code, the display was almost perfect except the outlier
shape.
Based on the following code, the outliers are vertical lines.
However, I want the outliers to be empty circles.
Please kindly help how to modify the code to change the outlier shapes.
Thank you.
code
package (lattice)
dataN <-
2010 Jan 02
2
Boxplot- input the median point and the median value
Dear,
I am a newbie to R.
Now I am learning to draw boxplot using graphics().
I want to highlight the median position
with a round point and the value left (or on the top of)to the point.
Please kindly share the command and thank you.
Elaine
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