Displaying 20 results from an estimated 9000 matches similar to: "cross validation for species distribution"
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 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
2009 Nov 02
1
modifying predict.nnet() to function with errorest()
Greetings,
I am having trouble calculating artificial neural network
misclassification errors using errorest() from the ipred package.
I have had no problems estimating the values with randomForest()
or svm(), but can't seem to get it to work with nnet(). I believe
this is due to the output of the predict.nnet() function within
cv.factor(). Below is a quick example of the problem I'm
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 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
2009 Apr 25
1
Overlapping parameters "k" in different functions in "ipred"
Dear List,
I have a question regarding "ipred" package. Under 10-fold cv, for different knn ( = 1,3,...25), I am getting same misclassification errors:
#############################################
library(ipred)
data(iris)
cv.k = 10 ## 10-fold cross-validation
bwpredict.knn <- function(object, newdata) predict.ipredknn(object, newdata, type="class")
for (i in
2005 Jan 06
1
different result from the same errorest() in library( ipred)
Dear all,
Does anybody can explain this: different results got when all the same parameters are used in the errorest() in library ipred, as the following?
errorest(Species ~ ., data=iris, model=randomForest, estimator = "cv", est.para=control.errorest(k=3), mtry=2)$err
[1] 0.03333333
> errorest(Species ~ ., data=iris, model=randomForest, estimator = "cv",
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 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 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.
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]]
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)
2010 Aug 14
1
color vector for green, red, blue
Dear list,
I am plotting dots using distinct colors according to the species.
Like the style of topo.colors(18), please kindly advise if any color vector
exists for green, red, and blue.
Thank you
Elaine
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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 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
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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2011 May 13
2
to check if a group of values is randomly distributed
Dear list,
I have 603 numbers depicting range sizes of birds in Japan.
I would like to learn if the 603 range sizes are randomly distributed or
not, in order to check if they meet mid-domain effects.
Please kindly advise if any R package or function can check the fit.
Also, any more references are highly appreciated.
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 <-