similar to: lm() notation question

Displaying 20 results from an estimated 10000 matches similar to: "lm() notation question"

2011 Mar 30
3
how about a "<p-" operator?
I was cursing Matlab again today (what else is new) because the default action for every Matlab command is to spew the result to the console, and one must remember to put that darn ";" at the end of every line. So I just wondered: was there ever a discussion as to providing some modified version of the "<-" and "->" operators in R to do the reverse?
2009 Nov 28
1
Include manually an intercept in lm without breaking it?
Hi Say I want to add manually an intercept in the function lm. Even if almost all results will be identical, few stats are different as DF counting will be different as intercept will not be included in "automatic" case, while it will be in "manual" case. See: ###usual lm on freeny fr<-lm(freeny.y~freeny.x) ###manual lm on freeny man<-cbind(1,freeny.x)
2009 Nov 29
1
lm: eval(parse(text=)) works on one side y/x but not on both?
Hi My goal is to do a (multiple) regression, just knowing that my Y variables will be the say k first variables of a matrix/data frame. I thought I should do it with eval(parse)) but encounter a strange problem. See: lm(y~.-y, data=freeny) #that's what I want to do in the one equation case #Problem is I don't know name of the variable... only that it is the first one... #so idea is to
2008 Mar 03
1
How to include an externally defined NULL value in lm
Hello! I would love to be able to include an external variable to a lm call, I mean something: if(TRUE) a<-freeny.x[,4] else a<-NULL lm(freeny.y~freeny.x[,-4] +a) but it does not work with a<-NULL, whereas lm(freeny.y~freeny.x[,-4] +NULL) I don't understand why and did not find an answer in the manuals... do you see it? Any idea? Thanks!!
2011 Jan 04
1
function masking and gmp questions
Hi, Here's the problem I ran into: the gmp package has a method for apply() so it masks the base::apply function. With gmp installed, I tried to run the function turnpoints() from the pastecs package. It fails because it calls apply() internally, like this: apply(mymatrix,1,max,na.rm=TRUE) , but the code in the gmp package which sets up the operator overload for apply() strictly
2010 Sep 04
1
tail.matrix returns matrix, while tail.mts return vector
Hi I have a few problems with tail/head when applied to multiple time series. I'm not sure as whether I did not understand the function or whether it correspond to an unexpected behavior. When head(a,n) is applied on data.frame or matrix, it returns a data-frame or matrix with first n obs of *each* variable. When applied to a mts object, it returns first n obs of *first* variable only,
2018 Mar 05
1
model.frame strips class as promised, but fails to strip OBJECT in C
Full thread here: https://github.com/tidyverse/broom/issues/287 Reproducible example: is.object(freeny$y) # [1] TRUE attr(freeny$y, 'class') # [1] "ts" class(freeny$y) # [1] "ts" # ts attribute wiped by model.frame class(model.frame(y ~ ., data = freeny)$y) # [1] "numeric" attr(model.frame(y ~ ., data = freeny)$y, 'class') # NULL # but still:
2009 Jan 12
3
lm: how are polynomial functions interpreted?
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1999 Feb 18
1
model.frame mangles time series (PR#121)
This one showed up while looking at one of Ripley's other reports: > data(freeny) > model.frame(y~1,data=freeny,subset=1:10) y 1962.25 8.79236 1962.5 8.79137 1962.75 8.81486 1963 8.81301 1963.25 8.90751 1963.5 8.93673 1963.75 8.96161 1964 8.96044 1964.25 9.00868 1964.5 9.03049 > model.frame(y~1,data=freeny,subset=1:10)$y Warning: Replacement length not a
2008 Nov 01
2
Hidden line algorithms and a different kind of waterfall
This is not the same as the recent thread on a waterfall graph. I'm thinking about the rolling FFT display used in acoustics and other spectrum analysis tasks. Here's an example of a very fancy 3-D waterfall display: http://www.ultimaserial.com/UltimaWaterfall.html I was just wondering if there are any simple hidden-line tools in R that I could use to draw simple waterfall displays.
2009 Jun 18
3
How to parse and eval a collection of items
Let's say I have, for some reason, a bunch of scalars (i.e. single-valued variables) and I want to merge them all into a single vector of values. Can someone recommend a better function, or simpler way, to do so than the following? Suppose my scalars' names are foo1, foo2, foo3, foo1high, foo2high, foo3lo2, etc. Then I can do: >ls(pat='foo')->thels
2012 Apr 03
2
Looking for the name of a certain kind of quantile plot
Hi, While playing with quantile-quantile plots, I wrote up some code which plots something strangely different. Here's the pseudocode: testhist <- hist(sample_data) refhist <- hist(rnorm(n, mean=0,sd=1)) # for some large-ish n cumtest <- cumsum(testhist) cumref <- cumsum(refhist) plot(cumref,cumtest) This produces a straight line of slope 1 for a sample with the same
2008 Oct 14
2
list syntax question: which subscript is which
Hi, Sorry to bother with something that should be simple, but I can't find it. Suppose I have a list, each element of which is a 2xN dataframe, where N could be different for each element. Is there some simple structure to let me examine all the elements of each element's first column? For example: >foo $first [,1] [,2] [1,] 1 4 [2,] 2 5 [3,] 3 6 $second
2011 Dec 13
2
axis tick colors: only one value allowed?
Hi, So far as I can tell, the 'col.ticks' parameter for axis() only uses the first value provided. E.g.: plot(0:1,0:1, col.ticks=c('blue','red','green')) #all ticks are blue Just wondering if there's a different option in the basic plot commands that can handle multiple colors, and also whether ggplot and/or lattice allow for multiple tick colors.
2008 Jun 07
3
favorite useful tools?
Hi, I'm relatively new to R, so I don't know the full list of base (or popular add-on packages) functions and tools available. For example, I tripped across mention of rle() in a message about some other problem. rle() turned out to be a handy shortcut to splitting some of my data by magnitude (vaguely like a sequence-based histogram). So I thought I'd ask: what small, or
2005 Feb 02
4
(no subject)
can you recommend a good manual for R that starts with a data set and gives demonstrations on what can be done using R? I downloadedR Langauage definition and An introduction to R but haven't found them overly useful. I'd really like to be able to follow some tutorials using a dataset or many datasets. The datasets I have available on R are Data sets in package 'datasets':
2011 Feb 02
4
testing randomness of random number generators with student t-test?
Hi, subject more or less says it all. I freely admit to not having bothered to find some of the online papers about method of testing the quality of random number generators -- but in an idle moment I wondered what to expect from something like the following: randa<-runif(1000) randb<-runif(1000) t.test(randa,randb)$p.value var.test(randa,randb)$p.value [repeat ad nauseum] Is the
2011 Aug 15
2
what can one do with (to) '..." ?
I followed a couple threads from the archives and from stackoverflow.com, and would like to know: just what is "..." ? What I mean by this is,for example, from the point of view of a user running a function in debug mode, is "..." an object, or does it exist in the current environment as some thingy? Maybe a better question to ask is: if I were to write some function
2009 Feb 08
3
general inverse solver?
Just wondering if there's an R package which does tricks similar to what TK!Solver does. TK!Solver, for those not lucky enough to have found it, basically allows one to define a bunch of equations, assign values to an arbitrary subset of the variables, from which it calculates (either directly when possible or back-solving when not) the values of the other variable(s). thanks Carl
2011 May 02
2
easy way to do a 2-D fit to an array of data?
Hi, I've got a matrix, Z, of values representing (as it happens) optical power at each pixel location. Since I know in advance I've got a single, convex peak, I would like to do a 2D parabolic fit of the form Z = poly((x+y),2) where x and y are the x,y coordinates of each pixel (or equivalently, the row, column numbers). Is there an R function that lets me easily implement that?