Displaying 20 results from an estimated 2000 matches similar to: "Using very large matrix"
2010 Mar 30
6
Error "singular gradient matrix at initial parameter estimates" in nls
I am using nls to fit a non linear function to some data.
The non linear function is:
y= 1- exp(-(k0+k1*p1+ .... + kn*pn))
I have chosen algorithm "port", with lower boundary is 0 for all of the
ki parameters, and I have tried many start values for the parameters ki
(including generating them at random).
If I fit the non linear function to the same data using an external
2009 Sep 01
3
Strange error returned or bug in gam in mgcv????
Dear friends,
what is this error message in gam???? I cannot understand what it means ....
is it a bug?
gam_bray_scot24_pc_0505<gam(bray~s(PC1,PC2,PC3,PC4,PC5,
PC1.1,PC2.1,PC3.1,PC4.1,PC5.1),data=dist_scot24_vector_with_climate)
Error in if (length(data) != vl) { :
missing value where TRUE/FALSE needed
Calls: gam ... smooth.construct -> smooth.construct.tp.smooth.spec -> array
In
2009 Sep 30
3
A point in a vector?
Dear list,
I have a strange requirement .... I have a vector, for example v<-
c(0,0,0,0,1,2,4,6,8,8,8,8). I have a value,for example x<- 4.8.
I would like to understand in which sub interval of v is x. In this case, v
would be in the sub interval [4,6] that is in the subinterval starting from
element j=7 to the element j+1=8.
Can we do that with an R command?
Regards
--
Corrado Topi
From THE R BOOK -> Warning: In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!
2010 Mar 30
3
From THE R BOOK -> Warning: In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!
Dear friends,
I am testing glm as at page 514/515 of THE R BOOK by M.Crawley, that is
on proportion data.
I use glm(y~x1+,family=binomial)
y is a proportion in (0,1), and x is a real number.
I get the error:
In eval(expr, envir, enclos) : non-integer #successes in a binomial glm!
But that is exactly what was suggested in the book, where there is no
mention of a similar warning. Where am I
2009 Sep 03
3
goodness of "prediction" using a model (lm, glm, gam, brt, regression tree .... )
Dear R-friends,
How do you test the goodness of prediction of a model, when you predict on a
set of data DIFFERENT from the training set?
I explain myself: you train your model M (e.g. glm,gam,regression tree, brt)
on a set of data A with a response variable Y. You then predict the value of
that same response variable Y on a different set of data B (e.g. predict.glm,
predict.gam and so on).
2009 Nov 25
3
Concave hull
Dear friends,
Do you know how to calculate the CONCAVE hull of a set of points (2-
dimensional or n-dimensional)? is that possible in R? (With a "smoothing"
parameter of course).
Best,
--
Corrado Topi
Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk
2009 Sep 10
2
Negative AIC
Dear R list,
I just obtained a negative AIC for two models (-221.7E+4
and -230.2E+4). Is that normal?
Regards
--
Corrado Topi
Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk
2008 Dec 11
2
Principal Component Analysis - Selecting components? + right choice?
Dear R gurus,
I have some climatic data for a region of the world. They are monthly averages
1950 -2000 of precipitation (12 months), minimum temperature (12 months),
maximum temperature (12 months). I have scaled them to 2 km x 2km cells, and
I have around 75,000 cells.
I need to feed them into a statistical model as co-variates, to use them to
predict a response variable.
The climatic
2009 Aug 24
2
Formulas in gam function of mgcv package
Dear R-experts,
I have a question on the formulas used in the gam function of the mgcv
package.
I am trying to understand the relationships between:
y~s(x1)+s(x2)+s(x3)+s(x4)
and
y~s(x1,x2,x3,x4)
Does the latter contain the former? what about the smoothers of all
interaction terms?
I have (tried to) read the manual pages of gam, formula.gam, smooth.terms,
linear.functional.terms but
2009 Aug 24
2
Formulas in gam function of mgcv package
Dear R-experts,
I have a question on the formulas used in the gam function of the mgcv
package.
I am trying to understand the relationships between:
y~s(x1)+s(x2)+s(x3)+s(x4)
and
y~s(x1,x2,x3,x4)
Does the latter contain the former? what about the smoothers of all
interaction terms?
I have (tried to) read the manual pages of gam, formula.gam, smooth.terms,
linear.functional.terms but
2009 Aug 27
19
Best R text editors?
Quick informal poll: what is everyone's favorite text editor for working
with R? I'd like to hear from people who are using editors that have
some level of direct R interface (e.g. Tinn-R, Komodo+SciViews). Thanks!
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The
2009 Oct 02
1
Fetch large sized file from SQL
Hi List,
Does any one know what package I need to use in order to fetch/get a large
sized dataframe from SQL? I have already used sqldf package which is good
for fetching large sized csv files.
Thanks
Alireza
[[alternative HTML version deleted]]
2010 Mar 23
1
S4: Multiple inheritance
Hi all,
Working with S4 object, I definine two class foo1 and foo2. I define '['
(resp. '[<-') for the two classes.
Then I define a third class foo3 that inherit from both foo1 and foo2.
Is there a way to make '[' (resp. '[<-') for foo3 inherit from '['
(resp. '[<-') for foo1 and foo2?
Thanks
Christophe
2011 Apr 29
2
Summer student internship placement at University of York / YCCSA / SEI (paid)
Dear R-lings,
I did not know which list to post to, because it is a studentship so not
really a job, so it did not fit the r-sig-jobs list .... and it is about
devloping an extension package interfaced with R .... I hope I did not upset
anyone. If so apologies.
The Centre For Complex systems Analysis at the University of York (YCCSA) in
UK in collaboration with Stockholm Environment
2011 May 03
1
Visiting Researcher, species distribution modelling, Cali, Colombia
Dear All,
The Decision and Policy Analysis (DAPA) program of the International Center
for Tropical
Agriculture (CIAT), a not-for-profit agriculture, biodiversity and
ecosystems research center,
supported by the Consultative Group of International Agricultural Research
(CGIAR), with
headquarters in Cali, Colombia is looking for a visiting researcher to work
on various modeling
projects, primarily
2009 Sep 29
4
Something wrong with my function Please Help
Hi R users,
I try to build a function to compute odds ratio and relative risk however
something wrong. I stuck for many hours but I really don't know how to solve
it. Would someone please give me a hint?
> OR.RR<-function(x){
+ x <- as.matrix(any(dim(x)==2))
+ OR<-(x[1,1]*x[2,2])/(x[1,2]*x[2,1])
+ RR<-(x[1,1]/(sum(x[1,])))/(x[2,1]/(sum(x[2,])))
+
2010 Mar 23
1
Changing content of column in data.frame + efficient join extraction between 2 data.frames
Dear R users,
I have 2 SpatialPointsDataFrame's, pcs and East.
The column str_1 in the first (pcs) is:
> pcs[0:4,]
coordinates cat str_1 int_1 int_2 dbl_1 dbl_2
1 (101000, 263000) 1 "SM06B" 101000 263000 4.978915 -4.293668
2 (101000, 265000) 2 "SM06C" 101000 265000 4.960478 -4.266742
3 (101000, 267000) 3 "SM06D" 101000 267000
2009 Sep 15
5
identical(length(x), 1) returns FALSE, but print(length(x)) is 1, length(x)==1 is TRUE, and is.integer(lenght(x)) is TRUE????
Dear R,
the condition:
identical(length(x),1) returns FALSE
but
print(length(x))
returns 1 and:
is.vector(x) is TRUE.
is.integer(length(x)) is TRUE
length(x) ==1 is TRUE
I am puzzled.
Regards
--
Corrado Topi
Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk
2009 Sep 28
6
SAS user now converting to R - Help with Transpose
I am just starting to code in R and need some help as I am used to doing this
in SAS.
I have a dataset that looks like this:
Chemical Well1 Well2 Well3 Well4
BOD 13.2 14.2 15.5 14.2
O2 7.8 2.6 3.5 2.4
TURB 10.2 14.6 18.5 17.3
and so on with more chemicals....
I would like to transpose my data so that it looks like this:
Chemical WellID Value
BOD Well1 13.2
BOD Well2 14.2
BOD Well3 15.5
BOD
2009 Sep 03
1
--enable-memory-profiling at configuration (compilation) time?
Dear Rfriends,
what is the option --enable-memory-profiling at configuration (just before build
+ install) time?
I did not find mention of it in the R admin manual (http://cran.r-
project.org/doc/manuals/R-admin.html).
Regards
--
Corrado Topi
Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645,