Monday, April 28: go over last data set with a fine tooth comb.
plus.two = function(x){
new=x+2
return(new)
}
Tuesday, April 29:
First 30 minutes:
Question 4:
Athletes performing in bright sunlight often smear black eye grease under their eyes to reduce glare. Does the eye grease work? In one study, 16 students too a test of sensitivity to contrast after 3 hours facing into bright sun: once with eye grease and once without. Here are the differences in sensitivity, with eye grease minus without eye grease:
0.07 0.64 -0.12 -0.05 -0.18 0.14 -0.16 0.03 0.05 0.02 0.43 0.24 -0.11 0.28 0.05 0.29
Run a hypothesis test to see whether or not we think the eye grease helps minimize sensitivity.
After that--two way table.
Question Zero: Scared of movies...?
Wednesday, April 30:
http://www.cyclismo.org/tutorial/R/tables.html
# creation of a table
scared <- matrix(c(40,70,50,90),ncol=2,byrow=TRUE)
colnames(scared) <- c("Male","Female")
rownames(scared) <- c("Jumped","Did Not Jump")
scared.t <- as.table(scared)
scared.t
FACT.
expected value is as follows:
row.total*column.total
---------------------- = expected value for that cell.
table.total
FACT.
we compare the expected value of a cell
to the actual value of a cell.
if the differences are big enough,
the difference is significant.
...we use chi squared test to check for that.
FACT. chi-squared of a single cell is...
(actual-expected)^2
------------------- = chi-squared value.
expected
FACT.
we do this by: summary(scared) <-- obv. change
scared for
new data.
Thursday, May 1: continue data set.
Friday, May 2: finish data set.