Displaying 20 results from an estimated 10000 matches similar to: "Find pattern in matrix"
2002 May 31
2
Matrix-like plot
Dear List,
I have a 47 species * 83 samples matrix containing percentage abundance
data. I have two cluster analyses one of the samples and one of the
species, and have ordered the rows and columns of the species by samples
matrix according to these two cluster analyses. So far so good!
Now what I want to do is create a plot with the species dendrogram at
the top of the plot, the samples
2011 Nov 07
2
ordination in vegan: what does downweight() do?
Can anyone point me in the right direction of figuring out what downweight()
is doing?
I am using vegan to perform CCA on diatom assemblage data. I have a lot of
rare species, so I want to reduce the influence of rare species in my CCA. I
have read that some authors reduce rare species by only including species
with an abundance of at least 1% in at least one sample (other authors use
5% as a
2013 Feb 28
1
help for an R automated procedures
Dear, I would like to post the following question to the r-help on Nabble (thanks in advance for the attention, Gustavo Vieira):
Hi there.
I have a data set on hands with 5,220 cases and I'd like to automate some
procedures (but I have almost no programming knowledge). The data has some
continuous variables that are grouped by 2 others: the name of species and
the locality where they were
2007 Jul 23
1
cca and cca.predict in vegan-what sort of prediction is possible
Hi All
I am not clear quite how one could use cca from package vegan and the associated
predict.cca to predict species abundance from environmental data (or if this is possible
in a generalised way). In other words, can one derive a cca object based on known
community data and use that to predict e.g. species abundances in a different number
of samples based on environmental data? The help
2008 Jun 16
1
candisc() error message
Hi,
I am doing canonical discriminant analysis using candisc function from
the candisc package.
My input is a table of species distribution (columns = abundance of each
species in each sample) in samples that are split by categories (rows),
and I want to know whether each category is associated with a particular
set of species and their abundances.
I have 20 rows (samples) split into 6
2008 Feb 09
1
Comparing spatial point patterns - Syrjala test
Dear Lists,
At several stations distributed regularly in space[1], we sampled
repeatedly (4 times) the abundance of organisms and measured
environmental parameters. I now want to compare the spatial
distribution of various species (and test wether they differ or not),
or to compare the distribution of a particular organism with the
distribution of some environmental variable.
2013 Jan 18
1
lattice: loess smooths based on y-axis values
Hi there,
I'm using the lattice package to create an xy plot of abundance vs. depth for 5 stages of barnacle larvae from 5 species. Each panel of the plot represents a different stage, while different loess smoothers within each panel should represent different species.
However, I would like depth to be on the y-axis and abundance to be on the x-axis, because this is more intuitive as an
2013 Jun 05
2
reshape2 issue continued
Hi again all,
Several replied ASAP that I also needed reshape loaded and not just
reshape2.
Hmmm tried that and I had some output but not the correct format.
What I need is to run simulations of time overlap between species as per
the simulation program data input constraints:
The basis for the simulations is a species by _time-use matrix in which
species are arranged in rows, and time
2009 May 01
3
adding zeros to dataframe
Greetings,
I am new to R and am hoping to get some tips from experienced R-programmers.
I have a dataset that I've read into R as a dataframe. There are 5 columns: Plot location,species name, a species number code (unique to each species name), abundance, and treatment. There are 272 plots in each treatment, but only the plots in which the species was recorded have an abundance value. For
2011 Feb 06
2
Subsampling out of site*abundance matrix
Hello,
How can I randomly sample individuals within a sites from a site (row) X
species abundance (column) data frame or matrix? As an example, the matrix
"abund2" made below.
##### (sorry, Im a newbie and this is the only way I know to get an example
on here)
abund1 <- c(150, 300, 0, 360, 150, 300, 0, 240, 150, 0, 60,
0, 150, 0, 540, 0, 0, 300, 0, 240, 300, 300,
2010 May 15
1
Barchart reorder
Hi fellow R users,
I have a dataset that looks something like this.
species class abundance
K 1 592
K 2 288
G 1 254
G 2 239
C 2 173
D 2 123
E 3 89
F 2 87
B 2 86
H 2 82
I 1 79
J 2 76
B 1 73
D 3 72
A 2 62
L 2 58
I want to plot a stacked barchart. species is the x-axis, abundance is
y-axis, and class will appear as the stacks in different colours. I
need the species to be displayed in descending
2004 Mar 02
2
Problem with Integrate
The background: I'm trying to fit a Poisson-lognormal distrbutuion to
some data. This is a way of modelling species abundances:
N ~ Pois(lam)
log(lam) ~ N(mu, sigma2)
The number of individuals are Poisson distributed with an abundance
drawn from a log-normal distrbution.
To fit this to data, I need to integrate out lam. In principle, I can
do it this way:
PLN1 <- function(lam, Count,
2009 Apr 29
1
How do I sample "cases" within a matrix?
Hi R community,
I am trying to obtain a sample from a matrix but sample(my.matrix) doesn't
do what I need. I have a matrix of 1287 interactions between the species in
columns and the species in rows and I want to obtain a smaller matrix with
say, 800 interactions, that may or may not have the same number of columns
and/or rows (i.e., some interactions may not be retrieved in a smaller
sample).
2011 Feb 10
2
Rioja package, creating transfer function, WA, "Error in FUN"
Hi, I am a new R user and am trying to construct a palaeoenvironmental
transfer function (weighted averaging method) using the package rioja.
I've managed to insert the two matrices (the species abundance and the
environmental data) and have assigned them to the y and x values
respectively. When I try and enter the 'WA' function though, I get an 'Error
in FUN' message (see
2012 Sep 24
6
Script to count unique values from two linked matricies
I hope you can help with this one.
I have two matricies:
1. A species abundance matrix:
<http://r.789695.n4.nabble.com/file/n4643979/2species_matrix.jpg>
2. A species trait score matrix:
<http://r.789695.n4.nabble.com/file/n4643979/2trait_matrix.jpg>
The trait matrix lists trait scores for each species as listed in the
species abundance matrix.
I would like to create a script
2007 Apr 01
4
Abundance data ordination in R
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2009 Feb 18
2
Counting/processing a character vector
Dear List,
I have a data set stored in the following format:
> head(dat, n = 10)
id sppcode abundance
1 10307 10000000 1
2 10307 16220602 2
3 10307 20000000 5
4 10307 20110000 2
5 10307 24000000 1
6 10307 40210000 83
7 10307 40210102 45
8 10307 45140000 1
9 10307 45630000 1
10 10307 45630600 41
>
2009 Sep 07
1
How to reduce memory demands in a function?
I've written a function that regularly throws the "cannot allocate vector of size X Kb" error, since it contains a loop that creates large numbers of big distance matrices. I'd be very grateful for any simple advice on how to reduce the memory demands of my function. Besides increasing memory.size to the maximum available, I've tried reducing my "dist" objects to 3
2012 Feb 14
1
cumsum function to determine plankton phenology
Apologies for the empty email earlier!
I have species abundance data sampled at a weekly frequency or
sometimes monthly depending on the year.
The goal is to identify the dates in an annual cycle in which the
cumulative abundance of a species reaches some threshold.
Here's an example of the data for 1 species over an annual period:
"mc_pheno" is the object created from this data:
2009 Jul 20
1
randomForest - what is a 'good' pseudo r-squared?
Hi all
I have been trying to use the randomForest package to model insect species abundance in different habitats and identify the key variables (landscape/climate etc) in determining abundance, which has all worked fine and I get nice variable importance plots etc. Many thanks to everyone on this help forum who has given tips/advice along the way.
But the percentage variance explained /pseudo r