similar to: R: expression

Displaying 20 results from an estimated 40000 matches similar to: "R: expression"

2005 Jul 21
3
R:plot and dots
hi all a very simple question. i have plot(x,y) but i would like to add in on the plot the observation number associated with each point. how can this be done? / allan
2004 Feb 03
3
R: plotting multiple functions
Hi all Another simple question. I would like to plot three graphs one the same plot with different colours. Say red, blue and black. Here are the functions. r1<-1+5*cos(2*pi*seq(1:100)/20)+rnorm(100) r2<-1+7*sin(2*pi*seq(1:100)/20)+rnorm(100) r3<-1+7*sin(2*pi*seq(1:100)/20)+5*cos(2*pi*seq(1:100)/20)+rnorm(100) Regards Allan
2004 Feb 24
5
r: plots
hi all i have another probably simple question. I have three variables say x, y and z. x and y are quite large and z is relative small. how can one plot the three variables on the same graph with two separate axis? (one for x and y and the other for z) e.g. x<-c(101,110,150,167,120) y<-c(120,135,175,95,200) z<-c(0.001, 0.15, 0.6, 0.8, 1) regards Allan
2005 Jul 29
5
R: graphics devices
a simple question how does one produce plots on two different graphics devices? / allan
2005 Apr 11
4
R: function code
HI sorry to be a nuisance to all!!! how can i see the code of a particular function? e.g. nnet just as an example
2010 Feb 11
1
Fwd: Recall function: "evaluation nested too deeply: infinite recursion / options(expressions=)?"
hello all i searched the archives and couldn't get a solution to the following question. i have the following function: F=function(z,v) { if (v==-.5) return(1) else return(2*v/z + 1/Recall(z,v-1)) } and while testing whether it works (ie F(z,v) is approx = besselK(z,1+v)/besselK(z,V). the recursion formula allows one to calculate besselK(z,1+v)/besselK(z,V) for large values of z )
2005 Mar 10
1
R: LIST function and LOOPS
hi all another simple question. i've written a dummy program so that you get the concept. (the code could be simplfied such that there are no loops. but lets leave the loops in for now.) z1<-function(w) { for (i in 1:w) { set.seed(i+6) ss<-0 for (j in 1:5) { set.seed(j+1+(i-1)*6) r<-rnorm(1) ss<-ss+r } list(ss=ss) } } check.1<-z1(3) check.1 the results is: $ss [1]
2004 Feb 10
6
R: lags
hi all how does one simulate a random walk process? i.e y(0)=0 y(t)=y(t-1)+ e(t) where e(t) is normal(0,1) say. Regards allan
2005 Mar 04
11
R: simulation
hi all a simple question i want to run simulations in r. i however want the experiments to be repeated at a later time with exactly the same numbers by other users. can i set the random number seed for rnorm in some way? e.g. is there some arguement that goes with rnorm? please supply an example regards Allan
2005 Feb 24
4
r: functions
hi all i have a function that uses two inputs, say xdata and ydata. An example is the following, simple1<-function(xdata,ydata) { ofit<-lm(ydata~xdata) list(ofit) } say i use arbitray number for xdata and ydata such that D = x1 x2 y 1 1 10 2 6 6 3 10 7 x<-D[,1:2] and y<-D[,3] if one uses these inputs and rund the program we get the following: >simple(xdata=x,ydata=y)
2007 Jul 24
7
Obtaining summary of frequencies of value occurrences for a variable in a multivariate dataset.
Hi all, If the question below as been answered before I apologize for the posting. I would like to get the frequencies of occurrence of all values in a given variable in a multivariate dataset. In short for each variable (or field) a summary of values contained with in a value:frequency pair, there can be many such pairs for a given variable. I would like to do the same for several such variables.
2008 Jan 22
1
R: determinants and inverses
hello all sorry for the following "none" R related question. does anyone know of a reference to calculate the following identity: |I + ABC| where I is an identity matrix and A, B,C may not have to be square matrices? you help will be greatly appreciated. H. V. Henderson; S. R. Searle SIAM Review, Vol. 23, No. 1. (Jan., 1981), pp. 53-60. provides a result to
2003 Dec 18
2
: Lp norm estimation
Hi all Just wondering whether one can undertake Lp norm estimation (a type of regression analysis) in R? i.e. argmin S ( | y(i) - x(i)b | ^p ) where: * S is the summation over observation i= 1,2,...,n * y is a vector of n observations * x is an n by p matrix of explanatory variables * b is a p by 1 vector of beta coefficients and * p is a constant to be estimated such that
2004 Dec 13
2
R: functions problem
hi all how can i see the code inside a particular function? i know one can simply type the function, eg ls, but sometimes when this is done one will get "UseMethod("some function name"). (One could also use "body" but i have the same problem in this case. )How does one see the code in this case?
2005 Oct 10
2
R: integration problem
hi all an integration problem. i would like an exact or good approximation for the following, but i do not want to use a computer. any suggestions: integral of exp(b*x)/sqrt(1-x^2) where "b" is a constant greater than or equal to 0 and the integral runs from 0 to 1 any help would be apreciated / allan
2007 Jun 08
2
legend + expression
Dear all; A simple? question. I'm having a problem with a math expression in the legend of a plot and I haven't found the way to get this to work, so any help will be appreciate. Basically I want to include in the plot is the R-squared and its numerical value, so I tried this: R2c<-0.82879 # R-squared of calibration model plot(1:10,1:10) legend("topleft",
2005 Sep 15
2
R: deleting rows
hi all hopefully some one can help. assume that i imported the following data into R (say the data frame is called a) x1 x2 x3 1 NA 3 1 2 NA 1 2 3 3 NA 6 4 5 9 7 5 6 7 8 9 NA 7 9 How can i construct a new data frame that only contains those rows that does not contain the NA's? is these a quick way? ie x1 x2 x3 1 2 3 4 5 9 7 5 6 7 8 9 in this example we can simple use
2005 Jul 29
1
R: non parametric regression/kernels
hi all i have a another stats question. i would like to solve the following question: y(i)=a+b*x(i)+e(i) i.e. estimate a and b (they should be fixed) but i dont want to specify the standard density to the straight line. this can be done using kernel regression. the fitted line is however fitted locally. does anyone have a reference that will help me with my problem. i am still new to
2008 Jan 25
2
Using bquote: question
Hi all Observe: x <- c(1,2) y <- c(1,-1) phi <- 1 p <- 2 par( mfrow=c(1,2)) plot(x , y, main=bquote( paste( p==.(p)," and ",phi==.(phi)) ) ) plot(y ~ x, main=bquote( paste( p==.(p)," and ",phi==.(phi)) ) ) par( mfrow=c(1,2)) On my system (details below), the first plot is correct (in my understanding), and produces a title reading "p=2 and phi=1"
2009 Feb 23
1
r: intergrate behaviour
hello R users strange behavior of the integrate function! i assume this occurs because of the way in which the quadriture is set up! (any comments.) f=function(x){exp(-exp(-x)-5*x)/gamma(5)} xx=seq(from=-20, to=20, length.out=1000) plot(xx,f(xx),type="l") integrate(f, lower=-Inf, upper= 1) integrate(f, lower=-Inf, upper= 10) integrate(f, lower=-10, upper= 11) integrate(f,