similar to: Compare species presence and absence between sites

Displaying 20 results from an estimated 4000 matches similar to: "Compare species presence and absence between sites"

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 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
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 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 [[alternative HTML version deleted]]
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 "
2013 Apr 24
2
Distance matrices Combinations
Dear UseRs, MY PROBLEM IS A SMALL PIECE OF A REAL BIG AND A COMPLICATED PROBLEM. IF I DELIBERATE IN A VERY SIMPLE WAY THEN ALL I WANT IS TO PUT ALL THE POSSIBLE COMBINATIONS OF 75 DISTANCE MATRICES (BY TAKING 4 MATRICES, MORE COMMONLY 75C4), in the following equation. t<-as.matrix((MAT1)^2+(MAT2)^2+(MAT3)^2+(MAT4)^2+,upper=T,diag=T)) Then "1215450" values of "t"(one for
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 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 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 <-
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 Oct 26
2
discerning plot dots using colors
Dear List, I am using the command plot to present the relationship between bird richness (Y axis) and elevation (X axis). However, I would like to observe the distributions of bird richness in different administrative areas (A, B, C, …., G) in this plot. For example, the dots in area A might fall in the upper right part of the plot, while those in area B might appear in the middle of
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]]
2013 Aug 24
1
Divide the data into sub data on a particular condition
Hi, Use ?split() #dat1 is the dataset: lst1<- split(dat1,dat1$BaseProd) lst1 #$`2231` ?# BaseProd? CF OSA #1???? 2231 0.5 0.7 #2???? 2231 0.8 0.6 #3???? 2231 0.4 0.8 # #$`2232` ?# BaseProd CF OSA #4???? 2232? 1?? 2 #5???? 2232? 3?? 1 # #$`2233` ?# BaseProd? CF OSA #6???? 2233 0.9 0.5 #7???? 2233 0.7 0.5 #8???? 2233 4.0 5.0 #9???? 2233 5.0 7.0 lst1[[1]] #? BaseProd? CF OSA #1???? 2231 0.5 0.7
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 [[alternative HTML version deleted]]
2013 Apr 18
6
count each answer category in each column
Hey, Is it possible that R can calculate each options under each column and return a summary table? Suppose I have a table like this: Gender Age Rate Female 0-10 Good Male 0-10 Good Female 11-20 Bad Male 11-20 Bad Male >20 N/A I want to have a summary table including the information that how many answers in each category, sth like this: X
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