DATA MINING Desktop Survival Guide by Graham Williams
Desktop Survival Project Home List of Figures List of Tables Data Mining Introduction Data Mining with Rattle Data Exploring Data Transforming Data Cluster Analysis Association Analysis Classification and Regression Models Evaluation and Deployment Issues Moving into R Troubleshooting Beyond Rattle R Data Graphics in R Understanding Data Preparing Data Descriptive and Predictive Analytics Issues Evaluating Models Reporting Cluster Analysis Text Mining Text Mining Algorithms Bagging Bayes Classifier Cluster Analysis Conditional Trees Hierarchical Clustering K-Nearest Neighbours Linear Models Neural Networks Support Vector Machines Open Products AlphaMiner Borgelt Data Mining Suite KNime R Rattle Weka Closed Products C4.5 Clementine Equbits Foresight GhostMiner InductionEngine ODM Enterprise Miner Statistica Data Miner TreeNet Virtual Predict Appendicies Installing GTK, R, and Rattle Glossary Bibliography Index

Logical

Objects of type logical take on the values TRUE or FALSE. The basic logical operators include:

!	Not	$<$	Less than	$<=$	Less than or equal to
$==$	Equal to	$>$	Greater than	$>=$	Greater than or equal to
&	And	|	Or	&& ||	Non vectorised versions

> 5 == 4        # FALSE
> 5 != 4 	# TRUE
> ! 1 - 1	# TRUE since 1-1 is 0 and is coerced to FALSE
> TRUE * 2	# 2 since TRUE is coerced to 1.

The single logical connectives & and | operates on vectors, whilst the double connective returns a single result, and does a minimal amount of comparison to get the result.

> c(TRUE, TRUE, FALSE) & c(TRUE, FALSE, FALSE)
[1]  TRUE FALSE FALSE
> c(TRUE, TRUE, FALSE) && c(TRUE, FALSE, FALSE)
[1] TRUE

The double form is usually what you want in an XnullXR functionsR functions (R function)R functionsR libraries (R library)R functionsR option (R option)R functionsR packages (R package)R functionsDatasets (Dataset)R functionsR functionsif statement.

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