Displaying 20 results from an estimated 9000 matches similar to: "how to display delta AIC of all models"
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
2010 Aug 17
2
Independent variables omitted in lm and glm
Dear List,
Some independent variable were missing in calculation using lm and glm
(gaussian).
(X= Y1+Y2+…..+Y16, Independent number: 16 variable)
However, those variables did work well in cor(X, Y) respectively.
str(dataframe) was also run to ensure that the variables were all numbers.
Moreover, the missing variables were different in lm and glm.
In lm, 3 factors were not taken into
2013 Apr 18
1
find lowest AIC of a LM
hello all,
I have a simple linear model with 4/5 variables that I am trying to fit.
I would like to find the lowest AIC value with any combination of all
the variables. I would like to implement this with a while/for loop.
Possibly I would like to generalize this so then I can use it when I
have many more variables. I do not want to use step AIC. At the moment I
am doing it manually but I
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
2010 Jun 20
2
compute coefficient of determination (R-squared) for GLM (maximum likelihood)
Dear,
I want to compute coefficient of determination (R-squared) to complement AIC
for model selection of
multivariable GLM.
However, I found this is not a built-in function in glm. neither is it
available through reviewing the question in the R-help archive.
Please kindly help and thanks a lot.
Elaine
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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
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 May 05
1
slope coefficient of a quadratic regression bootstrap
Hello,
I want to know if two quadratic regressions are significantly different.
I was advised to make the test using
step 1 bootstrapping both quadratic regressions and get their slope
coefficients.
(Let's call the slope coefficient *â*^1 and *â*^2)
step 2 use the slope difference *â*^1-*â*^2 and bootstrap the slope
coefficent
step 3 find out the sampling distribution above and
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 Jul 20
1
how to calculate the average values of each row in a matrix
Hello,
I have a matrix (class matrix) composed of GridCell (row and column).
The matrix value is the beta diversity index value between two grids.
Now I would like to get the average value of each GridCell.
Please kindly advise how to make the calculation.
Thank you.
Elaine
The matrix looks like (cited from Michael Friendly)
I would like to get the average value of each color.
Obs
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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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 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
2010 Sep 20
4
how to show the number of each axis interval (plot)
Dear List,
I am using plot for homework.
The x-axis covered from 0 to 80, with 4 intervals.
However, the plot only showed 0, 40, 80.
20 and 60 disappeared.
Please kindly advise how to show 0, 20, 40, 60, 80 for the axis interval.
Thank you.
Elaine
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2010 Sep 20
3
How to set the limit of abline (regression line of lm)
Dear List,
I ran a regression model using lm and produced a regression line using
abline.
The line ranges from -20 to 20 in x axis,
and the section I only want is from -20 to 0.
Please kindly advise any function in abline () to set the range of x axes.
Thank you
Elaine
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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 <-
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
Dear List,
This is Elaine, a postgraduate studying in bird distributions in East Asia.
I want to calculate Simpson dissimilarity index,
based on a presence/absence matrix of bird species in islands in East Asia.
(matrix row: 36 islands/matrix column: species ID)
(R package vegan to make NMDS and R package betapart)
In most papers using vegan for NMDS and betapart for dissimilarity
2010 Jun 29
2
process of stepwise selection
Dear list,
I wanna select the significant variables relative to bird distribution,
using stepwise method.
However, the result is always the best-fit model.
Please kindly suggest if it is possible to show the selection process.
Thank you
Elaine
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2010 Aug 24
4
how to plot y-axis on the right of x-axis
Dear List,
I have a richness data distributing across 20 N to 20 S latitude. (120 E-140
E longitude).
I would like to draw the richness in the north hemisphere and a regression
line in the plot
(x-axis: latitude, y-axis: richness in the north hemisphere).
The above demand is done using plot.
Then, south hemisphere richness and regression are required to be generated
using
the same y-axis above