bigBits (version 1.4)

base2base: Function which converts arbitrary-size integers from any base to any base.

Description

This function accepts inputs in any base from 2 through 36 and produces the same value in any selected base from 2 through 36. This includes options for signed and 2s complement binary data.

Usage

base2base(x,frombase=10, tobase=2, classOut=c('bigz', 'mpfr',
 'numeric','character') , binSize = 0, inTwosComp = FALSE,
   outTwosComp = FALSE )

Value

A list containing the converted value(s). Unless tobase is 10, each element is a character string. When tobase is equal to 10, the output class is specified with the argument classOut . Note: if an input or output is incompatible with the specified input or output base, a dummy value "%no" if character, or "NA" if a number-like class, is returned along with a warning message describing the error.

Arguments

x

A value or vector or list of values which are to be converted. The class can generally be numeric, mpfr, bigz, or character strings. Any fractional part is removed, leaving just the integer portion. See Details for more information.

frombase

The base of the input x. If the contents of x are incompatible with the specified base, a warning is issued and that value is skipped (i.e. if x has multiple values, base2base will keep running and process the other values). Default is 10

tobase

The desired base of the output. Default is 2.

classOut

Specify the class of the output. This only has meaning when tobase is 10; all other bases are returned as character strings. Warning: if the input is larger than the max integer size on your system and "numeric" is selected, there will be a roundoff/truncation error.

binSize

Specifies how many digits are to be generated. If this value is less than that necessary to contain the output value, the number of digits will be increased to match. If the output is binary, the final number of digits is expanded to a 4*N value. The default is zero, which allows the function to calculate the minimum bits required. Note: for obvious reasons, this only applies to character-class outputs.

inTwosComp

Only checked if frombase is 2. If FALSE, (the default), the input is positive unless a negative sign is present. If TRUE, the input is handled as a 2s complement binary.

outTwosComp

Only checked if tobase is 2. If FALSE, (the default), the output, if negative, includes a "-" sign. If TRUE, a 2's complement binary.

Author

Author and Maintainer:Carl Witthoft

Details

In general, when submitting an input in other than base 10, it's safest to provide a character string(s). There is some automagical conversion that will take, e.g., a numeric 364 with frombase = 8 and treat as base 8 (thus decimal 244), but this is not guaranteed. Further, keep in mind that numeric values with more than roughly 16 digits will likely run into floating-point precision errors. For base-10 inputs, use of bigz form is recommended. Inputs in hex format must be character strings. This is because the command parser converts, e.g., 0x3a, to the decimal value 58 prior to passing the value to the function body. Since, as noted above, base2base will attempt to convert a numeric input into the value in the base specified, base2base(0x3a, inbase= 16, ...) will in fact process the input as 58hex, i.e. 88 decimal.

See Also

strtoi as.hexmode fracB2B

Examples

(base2base(12.4e1,10,16))
(base2base(12.4e-2,10,16))
(base2base(101101,2,10))  # magic. it works!!!
(base2base('1111',2,2,inTwosComp=TRUE, outTwosComp=TRUE))
(base2base('0111',2,2,inTwosComp=TRUE, outTwosComp=TRUE))
(base2base('1111',2,2,inTwosComp=TRUE, outTwosComp=FALSE))
(base2base('0111',2,2,inTwosComp=TRUE, outTwosComp= FALSE))
(base2base(1e55,10,16)) #loses precision before even starting
(base2base('1e55',10,16)) #works
(base2base('1767707668033969' , 10, 36))