columns {strvalidator}

Column Actions

Description

Perform actions on columns.

Usage

columns(
  data,
  col1 = NA,
  col2 = NA,
  operator = "&",
  fixed = NA,
  target = NA,
  start = 1,
  stop = 1,
  debug = FALSE
)

Arguments

data

a data frame.

col1

character column name to perform action on.

col2

character optional second column name to perform action on.

operator

character to indicate operator: '&' concatenate, '+' add, '*' multiply, '-' subtract, '/' divide, 'substr' extract a substring.

fixed

character or numeric providing the second operand if 'col2' is not used.

target

character to specify column name for result. Default is to overwrite 'col1'. If not present it will be added.

start

integer, the first position to be extracted.

stop

integer, the last position to be extracted.

debug

logical to indicate if debug information should be printed.

Details

Perform actions on columns in a data frame. There are five actions: concatenate, add, multiply, subtract, divide. The selected action can be performed on two columns, or one column and a fixed value, or a new column can be added. A target column for the result is specified. NB! if the target column already exist it will be overwritten, else it will be created. A common use is to create a unique Sample.Name from the existing Sample.Name column and e.g. the File.Name or File.Time columns. It can also be used to calculate the Amount from the Concentration.

Value

data frame.

See Also

substr

Examples

# Get a sample dataset.
data(set2)
# Add concatenate Sample.Name and Dye.
set2 <- columns(data = set2, col1 = "Sample.Name", col2 = "Dye")
# Multiply Height by 4.
set2 <- columns(data = set2, col1 = "Height", operator = "*", fixed = 4)
# Add a new column.
set2 <- columns(data = set2, operator = "&", fixed = "1234", target = "Batch")