gen_random_expr {lazy.symbolic}

R Documentation

Generate Random Expression

Description

Generate Random Expression

Usage

gen_random_expr(
  natom = 2,
  nparen = 0,
  nparen2 = 0,
  random = 0,
  maxlena = 1,
  maxlennum = 0,
  oper = c("+", "-", "*"),
  alpha = c(letters, LETTERS),
  num = formatC(0:9, digits = 0, format = "d"),
  print = 0,
  debug = 0
)

Arguments

natom	# of atmic elements in an expression
nparen	# of parentheses in an expression
nparen2	# of higher level parentheses in an expression
random	= 1 to randomize the roots of the atomic elements
maxlena	# of alphabets in the root
maxlennum	# of numerics in the root
oper	a vector consisting of the binary operators to be used
alpha	a vector of characters to be used as the root
num	a vector of the numbers to be used as the root
print	= 1 to print the result = 2 to print the expanded result.

Details

This function generates a valid expression according to the specification given by the input parameters

Value

an expression as a character vector of length one

Examples

set.seed(1701)
gen_random_expr(  )
gen_random_expr( natom=9, random=1, nparen=3 )
set.seed(1701)
gen_random_expr( natom=9, random=1, nparen=3, nparen2=3 )
expr <- gen_random_expr( natom=9, random=0, nparen=3, nparen2=1
         , oper=c("%*%","+","-"), alpha=LETTERS[-9] )
expr <- sub( "D", "diag(D)", expr, fixed=1 )

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