Displaying 20 results from an estimated 2000 matches similar to: "Extrapolation of rarefaction curve"
2009 Nov 13
0
Rarefaction Curve by Individuals not Sites - vegan (specaccum)
Hi List,
I’m using the vegan function specaccum to produce a rarefaction curve. In
the function’s help it says: “Function ‘specaccum’ finds species
accumulation curves or the number of species for a certain number of sampled
sites or individuals”. Well, I would like to finds this curve for
individuals, but when I compute it the function (using the ‘rarefaction’
method) gives me Sites, Richness
2011 Nov 25
1
rarefaction curves: unable to run the R script from Gimlet
Hi everybody,
i'm trying to draw rarefaction curves to estimate a population size from
genotyped faeces.
I used the Gimlet software which gave me a script and a "rarefaction.txt"
file. I've copied both files in the work directory of R.
I changed library(nls) by library(stats) in the script.
But now, i'm still unable to run it.
If i ask to show error messages, the software
2024 Jan 14
0
Plotting extrapolation with R like AUTOBOX does
Dear R-experts,
I write to you to know if somebody is aware of a R package (or function) able to plot graphs for extrapolation.
I need to be clear on what extrapolation really is to me. It is when we use the model for X variables outside the range of X variables that were used to construct the model and estimates.?
What I am really looking for is that beyond confidence intervals for predictions
2010 May 26
2
Survival analysis extrapolation
Dear all,
I'm trying to fit a curve to some 1 year failure-time data, so that I can
extrapolate and predict failure rates up to 3 years. The data is in the
general form:
Treatment Time Status
Treatment A 28 0
Treatment B 28 0
Treatment B 28 0
Treatment A 28
2023 Oct 26
2
Plot for 10 years extrapolation
Dear R-Experts,
Here below my R code working but I don't know how to complete/finish my R code to get the final plot with the extrapolation for the10 more years.
Indeed, I try to extrapolate my data with a linear fit over the next 10 years. So I create a date sequence for the next 10 years and store as a dataframe to make the prediction possible.
Now, I am trying to get the plot with the
2001 Nov 13
1
rarefaction variance
Here's a question for ecologists on the r-help list-- I'm addressing this
to ecologists in particular because they're most likely to be familiar
with the equation in question but I'll be happy to discuss the problem
with anyone who's willing to take a whack at it.
I'm trying to write a function to calculate the large sample variance of
species richness estimates by
2006 Aug 04
0
Question regarding extrapolation
Hi,
I am facing a problem in extrapolation of data series. It is a series of
Bond yields, I am having the yield for 1 year to 30 years. I want to find
the yield for 0.5 year and 30.5 years. I used the Langrange's Extrapolation
but the extrapolation deviates from the normal trend ( as we can see in
theoritical yield curves) very sharply, as go on increasing my years from 30
years to 35 years
2012 May 21
0
linear extrapolation using data from imported text file
Dear?R experts,
?
I?am trying to do linear extrapolation on a dataset?like the attached document. I looked at the approx and approxfun function that seem to do this function, but not fully understand them. I was wondering if someone could help with writing commands to do the following based on the attached file's example:
?
ID#1 and ID?#2 both have response parameters ("MEASUREMENT"
2011 Jan 29
1
data extrapolation function
Readers,
Data was imported using the read csv command:
dataimport<-read.csv("/path/to/dataimport.csv")
10,2000
12,2001
13,2002
15,2003
17,2004
Using the help contents for 'predict.lm' (i.e. ?predict.lm) a new data
frame was created
dataimportextra<-data.frame(x=seq(1990,2010,1))
predict(lm(dataimport),dataimportextra[,2],se.fit=TRUE)
2007 Oct 05
0
use of specaccum in routine procedure
Dear list members, I have a data.frame so shaped:
Sector Quadrants Plot Sic Time Species1 Species2 Species3
.. Species-n
1 1 1 1 5 0 0 1
. 0
2 1 1 1 12 1 1 1
. 0
3 1 1 1 34 0 1 0
. 0
4 1 1 1 23 1 1 0
. 0
5 2 1 1 22 1 1 1
. 1
6 2 1 1 10 1 1 1
. 1
7 2 1 1 2 1 0 0
. 0
8 2 1 1 2 0 0 1
. 0
9 3 1 1 12 0 0 0
. 1
.
.
.
.
.
.
.
.
.
.
2009 Apr 14
4
Forcing the extrapolation of loess through the origin
Hi all,
I'm fitting a line to my dataset. Later I want to predict missing values that exceed the [min,max] interval of my empirical data, therefore I choose surface="direct" for extrapolation.
l1<-loess(y1~x1,span=0.1,data.frame(x=x1,y=y1),control=loess.control(surface="direct"))
In my application it is highly important that the fitted line intercepts at the point of
2007 Jul 30
0
problems in limma
Dear list members,
I am analysing my microarray data using limma package. Now I encounter
several problems. Looking forward to your suggestions!
Question 1:
During the process of background correction using method="normexp", four
warning messages appeared as "NaNs produced in: log(x)" (as you can see in
the program posted below). What does that mean? How will it effect the
2011 Apr 20
1
Extrapolating data points for individuals who lack them
Hi,
We have an experiment where individuals responses were measured over 5 days. Some responses were not obtained because we only allowed individuals to respond within a limited time-frame. These individuals are given the maximum response time as they did not respond, yet we feel they may have done if given time (and by looking at the rest of their responses over time, the non-response days stand
2008 May 04
1
adaptive optimization of mesh size
DeaR list,
I'm running an external program that computes some electromagnetic
response of a scattering body. The numerical scheme is based on a
discretization with a characteristic mesh size "y". The smaller y is,
the better the result (but obviously the computation will take longer).
A convergence study showed the error between the computed values and
the exact solution
2006 Nov 11
1
Fitting a survival curve
I am new to R and am trying to fit a survival curve with a weibull
hazard function to a set of data giving the probability of survival to
age x, given the year of birth, in the form:
Probability of survival:
Birth year
1980 1981 ... 2003
.2 0.90 0.89 ... 0.87
1 0.80 0.81 ... 0.79
age 2 0.75 0.74 ... 0.73
3 0.70 0.69 ... 0.68
5 0.50 0.49 ... 0.43
10 0.30 0.31 ... 0.26
I would like to be
2006 Apr 23
1
Comparing GLMMs and GLMs with quasi-binomial errors?
Dear All,
I am analysing a dataset on levels of herbivory in seedlings in an
experimental setup in a rainforest.
I have seven classes/categories of seedling damage/herbivory that I want to
analyse, modelling each separately.
There are twenty maternal trees, with eight groups of seedlings around each.
Each tree has a TreeID, which I use as the random effect (blocking factor).
There are two
2012 Sep 25
1
Extrapolating Cox predicted risk
Dear all
I generated predicted risk of death for each subject in the study by
means of Cox proportional hazards model at 8 year of follow-up, a time
point at which follow-up was more than 90% complete. It is possible to
extrapolate to 10-year the predicted risk of each subjet by assuming
an exponential distribution?
Any help would be greatly appreciated.
Thanks for your consideration.
2005 Dec 20
2
need 95% confidence interval bands on cubic extrapolation
Dear R experts:
I need to get this plot, but also with 95% confidence interval bands:
hour <- c(1, 2, 3, 4, 5, 6)
millivolts <- c(3.5, 5, 7.5, 13, 40, 58)
plot(hour, millivolts, xlim=c(1,10), ylim=c(0,1000))
pm <- lm(millivolts ~ poly(hour, 3))
curve(predict(pm, data.frame(hour=x)), add=TRUE)
How can the 95% confidence interval band curves be plotted too?
Sincerely,
2004 Mar 17
0
NLS question:Quadratic plus plateau fit
Dear R colleagues:
Am trying to fit a simple NL model to determine Economical Optimum Nitrogen
Rates.
The segmented (quadratic + plateau) model only works with some y's, in some
cases I get a "singular gradient" error.
I'll appreciate any ideas in how to solve the singular gradient error.
Thanks,
Jose
# The following code works using yield2 in the nls model but not using
2011 Jan 27
2
Extrapolating values from a glm fit
Dear R-help,
I have fitted a glm logistic function to dichotomous forced choices
responses varying according to time interval between two stimulus. x values
are time separation in miliseconds, and the y values are proportion
responses for one of the stimulus. Now I am trying to extrapolate x values
for the y value (proportion) at .25, .5, and .75. I have tried several
predict parameters, and they