R : Copyright 1999, The R Development Core Team
Version 0.90.0 Under development (unstable) (October 28, 1999)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type	"?license" or "?licence" for distribution details.

R is a collaborative project with many contributors.
Type	"?contributors" for a list.

Type	"demo()" for some demos, "help()" for on-line help, or
    	"help.start()" for a HTML browser interface to help.
Type	"q()" to quit R.

> options(error = expression(NULL)) # don't stop on error in batch
> ##~~~~~~~~~~~~~~
> 
> ###--------
>  x <- 1
> is.array(as.array( x ))
[1] TRUE
> is.call(as.call( x ))
Error in as.call(x) : invalid argument list
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
[1] TRUE
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
[1] TRUE
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
[1] TRUE
> is.integer(as.integer( x ))
[1] TRUE
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
[1] TRUE
> is.matrix(as.matrix( x ))
[1] TRUE
> is.name(as.name( x ))
[1] TRUE
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
[1] TRUE
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
[1] TRUE
> is.single(as.single( x ))
Error in is.single(as.single(x)) : type "single" unimplemented in R
> is.ts(as.ts( x ))
[1] TRUE
> is.vector(as.vector( x ))
[1] TRUE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
[1] TRUE
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
[1] TRUE
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
[1] TRUE
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
[1] TRUE
> 
> ###--------
>  x <- NULL
> is.array(as.array( x ))
Error in as.array(x) : attempt to set an attribute on NULL
> is.call(as.call( x ))
Error in as.call(x) : invalid argument list
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
[1] TRUE
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
[1] TRUE
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
Error in as.function.default(l, envir) : argument must have length at least 1
> is.integer(as.integer( x ))
[1] TRUE
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
[1] TRUE
> is.matrix(as.matrix( x ))
Error in array(x, c(length(x), 1), if (!is.null(names(x))) list(names(x),  : attempt to set an attribute on NULL
> is.name(as.name( x ))
Error in as.name(x) : invalid type/length (1/0) in vector allocation
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
[1] TRUE
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
[1] TRUE
> is.single(as.single( x ))
Error in is.single(as.single(x)) : type "single" unimplemented in R
> is.ts(as.ts( x ))
Error in ts(x) : ts object must have one or more observations
> is.vector(as.vector( x ))
[1] FALSE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
[1] TRUE
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
[1] TRUE
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
> 
> ###--------
>  x <- pi
> is.array(as.array( x ))
[1] TRUE
> is.call(as.call( x ))
Error in as.call(x) : invalid argument list
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
[1] TRUE
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
[1] TRUE
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
[1] TRUE
> is.integer(as.integer( x ))
[1] TRUE
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
[1] TRUE
> is.matrix(as.matrix( x ))
[1] TRUE
> is.name(as.name( x ))
[1] TRUE
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
[1] TRUE
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
[1] TRUE
> is.single(as.single( x ))
Error in is.single(as.single(x)) : type "single" unimplemented in R
> is.ts(as.ts( x ))
[1] TRUE
> is.vector(as.vector( x ))
[1] TRUE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
[1] TRUE
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
[1] TRUE
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
[1] TRUE
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
[1] TRUE
> 
> ###--------
>  x <- "1.3"
> is.array(as.array( x ))
[1] TRUE
> is.call(as.call( x ))
Error in as.call(x) : invalid argument list
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
[1] TRUE
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
[1] TRUE
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
[1] TRUE
> is.integer(as.integer( x ))
[1] TRUE
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
[1] TRUE
> is.matrix(as.matrix( x ))
[1] TRUE
> is.name(as.name( x ))
[1] TRUE
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
[1] TRUE
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
[1] TRUE
> is.single(as.single( x ))
Error in is.single(as.single(x)) : type "single" unimplemented in R
> is.ts(as.ts( x ))
[1] TRUE
> is.vector(as.vector( x ))
[1] TRUE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
[1] TRUE
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
[1] TRUE
> 
> ###--------
>  x <- list()
> is.array(as.array( x ))
[1] TRUE
> is.call(as.call( x ))
Error in as.call(x) : illegal length 0 argument
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
Error in as.complex.default(x) : (list) object cannot be coerced to vector type 15
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
Error in as.double.default(x) : (list) object cannot be coerced to vector type 14
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
Error in as.function.default(l, envir) : argument must have length at least 1
> is.integer(as.integer( x ))
Error in as.integer.default(x) : (list) object cannot be coerced to vector type 13
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
Error in as.logical.default(x) : (list) object cannot be coerced to vector type 10
> is.matrix(as.matrix( x ))
[1] TRUE
> is.name(as.name( x ))
Error in as.name(x) : (list) object cannot be coerced to vector type 1
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
Error in as.double.default(x) : (list) object cannot be coerced to vector type 14
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
Error in as.double.default(x) : (list) object cannot be coerced to vector type 14
> is.single(as.single( x ))
Error in structure(.Internal(as.vector(x, "double")), Csingle = TRUE) : (list) object cannot be coerced to vector type 14
> is.ts(as.ts( x ))
Error in ts(x) : ts object must have one or more observations
> is.vector(as.vector( x ))
[1] TRUE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
[1] TRUE
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
[1] TRUE
> 
> ###--------
>  x <- list(a = 1)
> is.array(as.array( x ))
[1] TRUE
> is.call(as.call( x ))
[1] TRUE
> is.character(as.character( x ))
[1] TRUE
> is.complex(as.complex( x ))
[1] TRUE
> is.data.frame(as.data.frame( x ))
[1] TRUE
> is.double(as.double( x ))
[1] TRUE
> is.expression(as.expression( x ))
[1] TRUE
> is.factor(as.factor( x ))
[1] TRUE
> is.function(as.function( x ))
[1] TRUE
> is.integer(as.integer( x ))
[1] TRUE
> is.list(as.list( x ))
[1] TRUE
> is.logical(as.logical( x ))
[1] TRUE
> is.matrix(as.matrix( x ))
[1] TRUE
> is.name(as.name( x ))
Error in as.name(x) : invalid type/length (1/1) in vector allocation
> is.null(as.null( x ))
[1] TRUE
> is.numeric(as.numeric( x ))
[1] TRUE
> is.ordered(as.ordered( x ))
[1] TRUE
> is.pairlist(as.pairlist( x ))
[1] TRUE
> is.qr(as.qr( x ))
Error in as.qr(x) : you cannot be serious
> is.real(as.real( x ))
[1] TRUE
> is.single(as.single( x ))
Error in is.single(as.single(x)) : type "single" unimplemented in R
> is.ts(as.ts( x ))
[1] TRUE
> is.vector(as.vector( x ))
[1] TRUE
> 
> if(is.array( x ))  all.equal(x, as.array( x ))
> if(is.call( x ))  all.equal(x, as.call( x ))
> if(is.character( x ))  all.equal(x, as.character( x ))
> if(is.complex( x ))  all.equal(x, as.complex( x ))
> if(is.data.frame( x ))  all.equal(x, as.data.frame( x ))
> if(is.double( x ))  all.equal(x, as.double( x ))
> if(is.expression( x ))  all.equal(x, as.expression( x ))
> if(is.factor( x ))  all.equal(x, as.factor( x ))
> if(is.function( x ))  all.equal(x, as.function( x ))
> if(is.integer( x ))  all.equal(x, as.integer( x ))
> if(is.list( x ))  all.equal(x, as.list( x ))
[1] TRUE
> if(is.logical( x ))  all.equal(x, as.logical( x ))
> if(is.matrix( x ))  all.equal(x, as.matrix( x ))
> if(is.name( x ))  all.equal(x, as.name( x ))
> if(is.null( x ))  all.equal(x, as.null( x ))
> if(is.numeric( x ))  all.equal(x, as.numeric( x ))
> if(is.ordered( x ))  all.equal(x, as.ordered( x ))
> if(is.pairlist( x ))  all.equal(x, as.pairlist( x ))
> if(is.qr( x ))  all.equal(x, as.qr( x ))
> if(is.real( x ))  all.equal(x, as.real( x ))
> if(is.single( x ))  all.equal(x, as.single( x ))
Error in is.single(x) : type "single" unimplemented in R
> if(is.ts( x ))  all.equal(x, as.ts( x ))
> if(is.vector( x ))  all.equal(x, as.vector( x ))
[1] TRUE
> 
>