Displaying 20 results from an estimated 100 matches similar to: "fitting allometric equation using a for a power model"
2012 Jun 01
1
trouble with append() in a for loop
Hello all,
*
*
I'm having some difficulty, and I think the problem is with how I'm using
append() nested inside a for loop. The data are:
y,x
237537.61,873
5007.148438,227
17705.77306,400
12396.64369,427
228703.4021,1173
350181.9752,1538
59967.79376,630
140322.7774,710
42650.07251,630
5382.858702,264
34405.82429,637
92261.34614,980
144927.1713,1094
362998.7355,1420
203313.6442,1070
2009 May 25
3
Interpolating variables within (RODBC library) SQL statements for MySQL
Hi everyone,
I am desperately looking for a method to interpolate strings within an SQL
statement as follows:
I get a lot of rows out of a database (in my example POSITION_to_ZIPCODE
Database with holds records for German ZIP Code <--> Gauss-Krueger
Coordinate System ) and want this to be selected and computed individually
row by row as follows:
library(RODBC)
channel <-
2009 Jun 16
1
adressing dataframes
Hi everyone,
I experience some problems with adressing of data.frames when I retrieve
some information for geographical position (ypos, xpos) ot of a MySQL
Database and want to perform some simple statistics. The problem is
adressing the dataframes with a construct like
rawdata[c(type)] vs. rawdata$TEMPMIN
to retrieve the numerical information and not a string (I want to store the
numerical
2000 Jun 21
3
SAS dataset
Hello,
Is there any way we convert SAS dataset into R dataset?
Kindest Regards,
Peppy Adi-Purnomo
------
Peppy Adi-Purnomo
Energy Market Analyst
Energy Link Ltd
Dunedin - New Zealand
Ph.: +64 3 479 2475
Fax: +64 3 477 8424
Email: s.adi.purnomo at energylink.co.nz
www.EnergyLink.co.nz
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r-help mailing list -- Read
2000 Nov 08
0
vq diffs
please add the following diffs to the vorbis/vq dir.
- include files changed so things actually compile in new scheme
- _ogg_...alloc cleanups caught a half-dozen typos or so
- minor Makefile touchup.
(stuff is still not tested, but this will compile at least)
Would someone with cvs write access commit them for me please?
Erik
diffs:
------------------------
diff -bBu2r vorbis/vq/Makefile
2011 May 16
1
Linear Discriminant Analysis error: "Variables appear constant"
Hi R experts,
I'm attempting to run Linear Discriminant Analysis using the lda function in the MASS package. I've got around 50 predictor variables and one response variable. My response variable has 5 numeric categories that represent different clusters of fish abundance data (clusters were developed using Bray-Curtis and NMDS), and my predictor variables are environmental variables that
2011 Mar 25
0
Bounding ellipse for any set of points
After a lot of effort I developed the following function to compute the
bounding ellipse (also known a as minimum volume enclosing ellipsoid) for
any set of points. This script is limited to two dimensions, but I believe
with minor modification the algorithm should work for 3 or more dimensions.
It seems to work well (although I don't know if can be optimized to run
faster) and
2012 Dec 03
0
Nested ANCOVA question
Hello R experts,
I have having a difficult time figuring out how to perform and interpret an ANCOVA of my nested experimental data and would love any suggestions that you might have.
Here is the deal:
1) I have twelve tanks of fish (1-12), each with a bunch of fish in them
2) I have three treatments (1-3); 4 tanks per treatment. (each tank only has one treatment applied to it)
3) I sampled
2011 Jul 21
0
Bounding ellipse for any set of points
The mvee() function is intended to be released under the BSD license.
Copyright (c) 2009, Nima Moshtagh
Copyright (c) 2011, Andy Lyons
All rights reserved.
http://www.opensource.org/licenses/bsd-license.php
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
Redistributions of source code must
2012 Dec 14
1
Define a custom-built loss function and combine it with nls()
Dear R helpers,
For an allometric analysis (allometric equation y = a*x^b) I would like
to apply a non-linear regression instead of using log-log
transformations of the measured parameters x and y and a Model II linear
regression. Since both of the variables x and y are random, I would like
to apply a Model II non-linear analog of either Reduced Major Axis or
Major Axis Regression.
The
2002 Dec 11
1
residuals: lm and glm
Dear list members,
I would like to know the difference in outputs and calculation processes
between residuals.glm(object, type="response") and residuals.lm(object).
For above-ground biomass estimation of trees, I estimated parameters of
an allometric equation (ln y = b0 + b1*ln x) using glm as follows:
fm <- glm(Ws~log(Wb), family=quasi(link="log",
2011 Nov 01
1
predict lmer
Dear all,
I've been reading for many days trying to predict with lmer but I haven't
managed to do it.
I've fitted an allometric model for trees where I have included climatic
variables and diameter in the fixed part and
in the random part I've included the experimental sites where trees are and
also their provenance region.
The model is like this :
2010 Aug 04
0
nls and geometric mean regression
Hello folks,
I'm seeking opinions about the validity of the following use of the
nls function...
A colleague and myself are working with tree allometric data
consisting of measurements of individual trees in semi-arid Australian
woodland species. We need to make predictions of trunk diameter (DBH:
diameter at breast height) given tree height and vice versa. I _think_
this falls into the
2008 Oct 21
0
Major Axis residuals
I am having trouble extracting residuals from Major Axis and
Standardized Major Axis fits, using the smatr package. I wish to
understand the relationship between density of wood in twigs and
trunks, and how the slope of their relationship varies among sites,
among families, and with tree size. These variance-partitioning
desires push the analysis toward a mixed model framework. However,
2012 May 11
0
Additional info: help with SMATR: help with pairwise comparisons using MA regression?
Also, this works (taking out multcomp=TRUE, multcompmethod="adjusted"):
com.test=ma(Head.W1~Leg.3.1+Site, type="elevation", data=queens)
print(com.test)
....so for some reason it will do an MA regression on all my data
point together, but shows an error when I try to do pairwise
comparisons between groups.
Thank you,
Ioulia
--------
On Fri, May 11, 2012 at 2:09 AM, Ioulia
2001 Sep 12
1
nonlinear fitting when both x and y having measurement e
Sorry, for disturbing the list again.
> Also I got one suggestion of using ORDPACK at http://www.netlib.org/.
It's ODRPACK at http://www.netlib.org/, not ORDPACK.
Best,
--
Etsushi Kato
ekato at ees.hokudai.ac.jp
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Send
2005 May 12
2
tempsum
hi,
i'd like to calculate a temperatursum, adding the value of each element.
let's say the data looks like this:
x<-c(1,2,3,4,5)
what i want to do, is ploting not the sum in the end but all the
subresults, too,
so my vector holds:
x[i]
[1]
1,3,6,10,15
here is what i tried, which seems to be right to me, bu doesn't work out:
x<-c(1,2,3,4,5)
i<-1
j<-1
2007 Feb 18
3
User defined split function in rpart
Dear R community,
I am trying to write my own user defined split function for rpart. I read
the example in the tests directory and I understand the general idea of the
how to implement user defined splitting functions. However, I am having
troubles with addressing the data frame used in calling rpart in my split
functions.
For example, in the evaluation function that is called once per node,
2013 Mar 28
1
make R program faster
Hi
there are some good tips in "The R Inferno"
http://www.burns-stat.com/documents/books/the-r-inferno/
or connect C++ to R with Rcpp
http://dirk.eddelbuettel.com/code/rcpp.html
or byte code compiler (library(compiler))
or library(data.table)
but do you have an idea to fasten standard R source code, with the
following Rprof output
self.time self.pct total.time
2007 Jul 25
0
Function polr and discrete ordinal scale
Dear all,
To modelize the abundance of fish (4 classes) with a set of environmental variables, I used the polr and predict.polr functions. I would like to know how to bring the cumulated probabilities back to a discrete ordinal scale.
For the moment I used the predict.polr function with the argument "class". Is there an other way?
polrf <- polrf <- polr_mod(formula =