Homologation of regressions — reg.homog • agricolae

It makes the regressions homogeneity test for a group of treatments where each observation presents a linearly dependent reply from another one. There is a linear function in every treatment. The objective is to find out if the linear models of each treatment come from the same population.

reg.homog(trt, x, y)

Arguments

trt	treatment
x	independent variable
y	dependent variable

Value

list objects:
Number regressions.
Residual.
Difference of regression.
DF.homgeneity (homogenity degree free).
DF.Residual (degree free error).
F.value. Test statitics.
P.value. P Value (Significant
Criterion. conclusion

References

Book in Spanish: Metodos estadisticos para la investigacion. Calzada Benza 1960

Examples


library(agricolae)
data(frijol)
evaluation<-with(frijol,reg.homog(technology,index,production))
#> 
#> Test of Homogeneity of regressions
#> 
#> Total of simple regressions:  4 
#> Total of residual          :  1680508 
#> Difference for homogeneity :  95331.6 
#> 
#> D.f. for the homogeneity   :  3 
#> Residual degrees of freedom:  76 
#> F calculated value         :  1.437106 
#> P.value                    :  0.2385897 
#> 
#> Criterion                  :  homogeneity of regressions exists 
#> 
# Example 2. Applied Regression Analysis a Research tools
# 1988. John O.Rawlings. Wadsworth & brooks/cole Advanced Books
# & Software. Pacific Grove. Califonia.
# Statistics/probability. Series
LineNumber<-c(rep("39","30"),rep("52","30"))
PlantingDate<-rep(c("16","20","21"),20)
HeadWt <- c(2.5,3.0,2.2,2.2,2.8,1.8,3.1,2.8,1.6,4.3,2.7,2.1,2.5,2.6,3.3,4.3,
2.8,3.8,3.8,2.6,3.2,4.3,2.6,3.6,1.7,2.6,4.2,3.1,3.5,1.6,2.0,4.0,1.5,2.4,2.8,
1.4,1.9,3.1,1.7,2.8,4.2,1.3,1.7,3.7,1.7,3.2,3.0,1.6,2.0,2.2,1.4,2.2,2.3,1.0,
2.2,3.8,1.5,2.2,2.0,1.6)
Ascorbic <-c(51,65,54,55,52,59,45,41,66,42,51,54,53,41,45,50,45,49,50,51,49,
52,45,55,56,61,49,49,42,68,58,52,78,55,70,75,67,57,70,61,58,84,67,47,71,68,
56,72,58,72,62,63,63,68,56,54,66,72,60,72)
trt<-paste(LineNumber,PlantingDate,sep="-")
output<-reg.homog(trt,HeadWt,Ascorbic)
#> 
#> Test of Homogeneity of regressions
#> 
#> Total of simple regressions:  6 
#> Total of residual          :  1847.236 
#> Difference for homogeneity :  127.817 
#> 
#> D.f. for the homogeneity   :  5 
#> Residual degrees of freedom:  48 
#> F calculated value         :  0.6642589 
#> P.value                    :  0.6523045 
#> 
#> Criterion                  :  homogeneity of regressions exists 
#>