Re: [R] QQ plotting of various distributions...

#same shape some_data <- rgamma(500,shape=6,scale=2) test_data <- rgamma(500,shape=6,scale=2) plot(sort(some_data),sort(test_data)) # You can also use qqplot(some_data,test_data) abline(0,1) # different shape some_data <- rgamma(500,shape=6,scale=2) test_data <- rgamma(500,shape=4,scale=2) plot(

Re: [R] plotting least-squares regression against x-axis

x <- seq(50) y <- 10 + x * 2 + rnorm(50,0,10) plot(y~x) mylm = lm(y~x) # Use str(mylm) to see how to get the residuals plot(x,mylm$residuals) On Sat, Sep 19, 2009 at 8:35 PM, Jason Priem wrote: > Hi, > I want to plot the residuals of a least-squares regression. > > plot(lm(y~x), which=1) >

Re: [R] What does model.matrix() return?

This describes the way in which categorical variables are coded in the model. In this case, we see "treatment" coding, although this can go by different names in textbooks (for example, reference cell coding). attr(,"assign") [1] 0 1 2 2 means that the first column of the model matrix corresponds

Re: [R] lean text label below barplot table

#Example data df <- data.frame(trt = factor(c("A long label", "Another long \n label")), outcome = c(1,4)) #Install ggplot2 if needed library(ggplot2) p <- ggplot(df, aes(y=outcome, x=trt)) p <- p + geom_bar(position="dodge", stat="identity") p <- p + opts(axis.text.x = theme_text(angle = 45, hj

Re: [R] standard error associated with correlation coefficient

Here are some options for confidence intervals. #by hand sample_r <- .5 n_sample <- 100 df <- n_sample-1 fisher_z <- 0.5*(log(1+sample_r)-log(1-sample_r)) se_z <- 1/sqrt(n_sample-3) t_crit <- qt(.975,df ,lower.tail=TRUE) z_lci <- fisher_z - (t_crit * se_z) z_uci <- fisher_z + (t_crit * se_z) (r_l

Re: [R] Select values at random by id value

#Highlight the text below (without the header) # read the data in from clipboard df <- do.call(data.frame, scan("clipboard", what=list(id=0, date="",loctype=0 ,haptype=0))) # split the data by date, sample 1 observation from each split, and rbind sampled_df <- do.call(rbind, lapply(split(df, df$

Re: [R] text() to label points in ggplot

# Here are two options: p <- ggplot(mtcars, aes(wt, mpg)) + geom_point() + geom_text(aes(x = 5, y = 30, label = "A Label")) #or response <- c(2,4) xvar <- c(1,2) label <- response; myData <- data.frame(response,xvar,label) p <- ggplot(myData, aes(y=response, x=xvar)) p + geom_bar(position="dodge

Re: [R] how to control lattice plot parameters

We can see the plotting options using trellis.par.get(). For example, one listed parameter is $superpose.line for which we can set col, lty, and lwd. Load the mlmRev package to obtain the Gcsemv data (used in Lattice book). One way to set the parameters is data(Gcsemv, package = "mlmRev") my.font

Re: [R] loglm fitting

If we check the data, we see a mistake in the entry. > tbl.8.3 mara cig alc count 1 Yes Yes Yes 911 2 No No No 538 3 Yes Yes Yes44 4 No No No 456 5 Yes Yes Yes 3 6 No No No43 7 Yes Yes Yes 2 8 No No No 279 Try: table8.3 <- read.table(textConnection("