# friedman: Friedman test and multiple comparison of treatments In agricolae: Statistical Procedures for Agricultural Research

## Description

The data consist of b-blocks mutually independent k-variate random variables Xij, i=1,..,b; j=1,..k. The random variable X is in block i and is associated with treatment j. It makes the multiple comparison of the Friedman test with or without ties. A first result is obtained by friedman.test of R.

## Usage

 `1` ```friedman(judge,trt,evaluation,alpha=0.05,group=TRUE,main=NULL,console=FALSE) ```

## Arguments

 `judge` Identification of the judge in the evaluation `trt` Treatment `evaluation` Variable `alpha` Significant test `group` TRUE or FALSE `main` Title `console` logical, print output

## Details

The post hoc friedman test is using the criterium Fisher's least significant difference (LSD)

## Value

 `statistics` Statistics of the model `parameters` Design parameters `means` Statistical summary of the study variable `comparison` Comparison between treatments `groups` Formation of treatment groups

## Author(s)

Felipe de Mendiburu

## References

Practical Nonparametrics Statistics. W.J. Conover, 1999

`BIB.test`, `DAU.test`, `duncan.test`, `durbin.test`, `HSD.test`, `kruskal`, `LSD.test`, `Median.test`, `PBIB.test`, `REGW.test`, `scheffe.test`, `SNK.test`, `waerden.test`, `waller.test`, `plot.group`

## Examples

 ```1 2 3 4 5 6 7``` ```library(agricolae) data(grass) out<-with(grass,friedman(judge,trt, evaluation,alpha=0.05, group=TRUE,console=TRUE, main="Data of the book of Conover")) #startgraph plot(out,variation="IQR") #endgraph ```

### Example output

```Study: Data of the book of Conover

trt,  Sum of the ranks

evaluation  r
t1       38.0 12
t2       23.5 12
t3       24.5 12
t4       34.0 12

Friedman's Test
===============
Critical Value: 8.097345
P.Value Chisq: 0.04404214
F Value: 3.192198
P.Value F: 0.03621547

Post Hoc Analysis

Alpha: 0.05 ; DF Error: 33
t-Student: 2.034515
LSD: 11.48168

Treatments with the same letter are not significantly different.

Sum of ranks groups
t1         38.0      a
t4         34.0     ab
t3         24.5      b
t2         23.5      b
```

agricolae documentation built on Sept. 13, 2017, 1:03 a.m.