Displaying 20 results from an estimated 4000 matches similar to: "compute coefficient of determination (R-squared) for GLM (maximum likelihood)"
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
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
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 Jan 08
4
error in a abline loop
Hello
I have data of body length and body weight of people of different skin colors.
I tried to write a code to plot body length and body weight according
to the skin colors.
(Thanks for Petr's advice so far.)
A loop is used but an error shows up in the following code.
It says:
unexpected '}' in
"
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)
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
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
[[alternative HTML version deleted]]
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
[[alternative HTML version deleted]]
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
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 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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2013 May 01
2
significantly different from one (not zero) using lm
Hello,
I am work with a linear regression model:
y=ax+b with the function of lm.
y= observed migration distance of butterflies
x= predicted migration distance of butterflies
Usually the result will show
if the linear term a is significantly different from zero based on the
p-value.
Now I would like to test if the linear term is significantly different from
one.
(because I want to know
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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2013 Feb 07
2
how to draw confidence interval lines of a fitted curve of polynominal regression
Hello,
I drew a plot of weight and height of people and fitted it with a
polynominal regression x^2.
(using curve())
Now I would like to draw the confidence interval line for the fitted curve.
Please kindly advise the code for the purpose.
Thank you.
Elaine
[[alternative HTML version deleted]]
2010 Jul 18
1
producing biplot of canonical correlation analysis
Dear List,
I would like to obtain biplot containing arrows and variable labels.
However, after checking the previous message and package CCA and function
anacor,
my attempt remains an open question.
Please kindly advise code or package I might miss to achieve it.
Thank you.
Elaine
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2012 Aug 27
1
how to generate response variables using simple regression
Hello,
I have weight and wing length data of 5 kinds of birds (B1 to B5).
Weight data (predictor) and wing data (response) were used to generated a
simple regression.
(using lm)
Now some weight data are found but without wing data (B6, B7).
I want to use the generated simple regression to produce wing data of B6
and B7 by their weight data.
Please kindly advise R code to carry it out.
Thank you.
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 Oct 29
1
change lm log(x) to glm poisson
Hello list,
I am running a regression using
lm(Y~A+B+log(C)+log(D))
Now, I would like to test if glm can produce similar results.
So the code was revised as
glm(Y~A+B+C+D, family=poisson) (code 1)
However, I found some example using glm for lm.
It suggests that the code should be revised like
glm(Y~A+B+log(C)+log(D), family=poisson) (code 2)
Please kindly advise which code is correct.