Displaying 2 results from an estimated 2 matches for "cs137".
2006 Jan 04
4
Discrepency between confidence intervals from t.test and computed manually -- why?
I am sure there is something simple here I am missing, so please bear
with me.
It concerns the computation of the confidence interval for a population
mean.
The data are 125 measurements of Cs137 radation, a sample data set from
Davis "Statistics and Data Analysis in Geology" 3rd ed. (CROATRAD.TXT)
------------------
method 1: using textbook definitions: mean \pm se_mean * t-value
mu <- mean(Cs137); n <- length(Cs137)
se.mean <- sqrt(var(Cs137)/n)
# two-tail alphas
alpha...
2005 Jun 22
1
How to use expression in label with xYplot
...ist,
I want to use the label function (from Hmisc library) to allow for the
names of my isotopes.
library(Hmisc)
library(lattice)
library(grid)
num <- c("78","137","129m")
nom <- c("Ge","Cs","Te")
df <- data.frame(GE78=seq(nom),CS137=seq(nom),TE129m=seq(nom))
if I use this function to create the labels :
lab <- function(i)
as.expression(bquote(italic(phantom(0)^{.(num[i])}*.(nom[i]))))
label(df$GE78) <- lab(1)
label(df$CS137) <- lab(2)
label(df$TE129m) <- lab(3)
all works fine when I use text and xyplot :...