Software to Simplify Statistical Practice ...

One-Way ANOVA - Example

 

Data

Source: http://www.itl.nist.gov/div898/handbook/eda/section3/eda3581.htm

 

 

Analysis

  1. Open the DataBook gear.vstz
    open this data file via the Help / Open Examples menu; it is in the Sample Data
  2. Choose the menu Analyze and the command One-Way, under group Analysis of Variance
  3. In Variables, select diameter
  4. In Grouping Variable, select batch
  5. Click OK

 

 

Output

By default, R code is printed after parsing and before evaluation.
You can avoid this in File / Option / Advanced menu.

DataSheet is converted to DataFrame, in the form DataBook.DataSheet

> ## Save variables.
> diameter <- gear.Sheet1$diameter
> batch <- as.factor(gear.Sheet1$batch)

> ## Fit one-way anova model.
> AnovaModel <- aov(diameter ~ batch)
> AnovaModel
Call:
   aov(formula = diameter ~ batch)

Terms:
                     batch  Residuals
Sum of Squares  0.00072904 0.00317400
Deg. of Freedom          9         90

Residual standard error: 0.005938574
Estimated effects may be unbalanced

> summary(AnovaModel)
            Df   Sum Sq   Mean Sq F value Pr(>F)  
batch        9 0.000729 8.100e-05   2.297 0.0227 *
Residuals   90 0.003174 3.527e-05                 
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

> summary.vst(gear.Sheet1$diameter , groups=gear.Sheet1$batch, statistics=c('mean',
'sd','nrow'))
     Statistic
Group   mean nrow          sd
   1  0.9980   10 0.004346135
   2  0.9991   10 0.005216427
   3  0.9954   10 0.003977716
   4  0.9982   10 0.003852849
   5  0.9919   10 0.007578478
   6  0.9988   10 0.009886017
   7  1.0015   10 0.007877535
   8  1.0004   10 0.003627059
   9  0.9983   10 0.004137901
   10 0.9948   10 0.005329165

 

 

Results

 

 

Resource