Generating Frequency Tables, r provides many methods for creating frequency and contingency tables.
One downside to this process is leverage season 5 episode 15 that the the names of the new fields are V1, V2, V3, etc.
This example will calculate the mean ability score and number of attendance days grouped by year and grade.
Test( x ) function to perform a Cochran-Mantel-Haenszel chi-squared test of the null hypothesis that two nominal variables are conditionally independent in each stratum, assuming that there is no three-way interaction.To get this data, install and load the eeptools package and then open the sample data by running the following code in R: # Install eeptools ckages eeptools # Load eeptools library(eeptools) # Open data data(stulevel the first example shows how to aggregate data.Loglinear Models You can use the loglm( ) function in the mass package to produce log-linear models.Even the "cleanest" installations cannot avoid cable capacitance or "skin effect" associated with long cable runs that deteriorate signal performance.Test( x ) provides an exact test of independence.Of course copper-clad steel is a lot stronger than bare copper, something that has saved many a catv/broadband installer who was less than gentle when installing such a the next time the salesperson is telling you about the "skin effect" in his speaker cable, well.Table(mytable, 1) # A frequencies (summed over B) margin.# 3-Way Frequency Table mytable - xtabs(ABc, datamydata) ftable(mytable) # print table summary(mytable) # chi-square test of indepedence.R (the resistance of the wire) is a major factor at low frequencies.The fifth step is to actually aggregate with data.
And at high frequencies, that's the only thing working.
Table, loaded the data, and setkey.
Table) # Convert stulevel to data table stulevel - data.
It has a wealth of options.
X is a two dimensional contingency table in matrix form.
All the DC power will be going down the steel wire, which is seven times the resistance of copper.What happened to the resistance?The #1 bone of contention with my wife is number of magazines get delivered to our house.See Richard Darlington's article on Measures of Association in Crosstab Tables for an excellent review of these statistics.If all you were carrying was high frequencies, you could use a copper tube as a conductor with no additional loss compared to a solid conductor.