nlmixr2auto (version 1.0.0)

.twoBitCode: 2-bit code helper

Description

Internal utility used by decodeBinary() and encodeBinary() to convert between a 2-bit representation and categorical values via lookup tables.

Usage

.twoBitCode(
  mode = c("decode", "encode"),
  value,
  bit2 = NULL,
  decode_map = NULL,
  encode_map = NULL,
  param_name = "param"
)

Value

For decode: a single numeric categorical value. For encode: an integer vector length 2 containing bits c(bit1, bit2).

Arguments

mode

Character, either "decode" or "encode".

value

For decode: the first bit (0/1). For encode: the categorical value to encode.

bit2

For decode: the second bit (0/1). Ignored for encode.

decode_map

Numeric vector of length 4 used for decoding, in the order corresponding to 00, 01, 10, 11. Use NA for illegal codes.

encode_map

Named integer/numeric vector mapping categorical values (as names) to integer codes 0..3 (corresponding to 00..11).

param_name

Character, parameter name used in error messages.

Author

Zhonghui Huang

Details

The helper supports two modes:

• decode: converts (bit1, bit2) to a categorical value using a length-4 lookup table decode_map corresponding to 00, 01, 10, 11.

• encode: converts a categorical value to a 2-bit code using a named lookup table encode_map mapping values to integer codes 0..3 (corresponding to 00..11).

See Also

decodeBinary, encodeBinary

Examples

# Decode example (00/01 map to level 1).
.twoBitCode("decode", 0, 0, decode_map = c(1, 1, 2, 3))  # 1
.twoBitCode("decode", 0, 1, decode_map = c(1, 1, 2, 3))  # 1
.twoBitCode("decode", 1, 0, decode_map = c(1, 1, 2, 3))  # 2
.twoBitCode("decode", 1, 1, decode_map = c(1, 1, 2, 3))  # 3

# Encode example (level 1 emits 01).
encode_map <- stats::setNames(c(1, 2, 3), c(1, 2, 3))
.twoBitCode("encode", 1, encode_map = encode_map)  # c(0, 1)
.twoBitCode("encode", 2, encode_map = encode_map)  # c(1, 0)
.twoBitCode("encode", 3, encode_map = encode_map)  # c(1, 1)

# Decode 4-level example (00..11 map to 1..4).
.twoBitCode("decode", 0, 0, decode_map = c(1, 2, 3, 4))  # 1