Subtract infrared spectra

ir_subtract takes two objects of class ir, x and y, and subtracts the intensity values of spectra in matching rows from y from that of x. Alternatively, takes an object of class ir, x, and a numeric value, y, and subtracts y from all intensity values in x.

Usage

ir_subtract(x, y)

Arguments

x

An object of class ir.

y

An object of class ir or a numeic value. If y is an object of class ir, it must have the same number of rows as x and the same x axis values (e.g. wavenumber values) in each matching spectrum as in x.

Value

x where for each spectrum the respective intensity values in y are subtracted (if y is an object of class ir), or where for each spectrum y has been subtracted from the intensity values.

Examples

# subtracting two objects of class ir
x1 <-
  ir::ir_subtract(ir::ir_sample_data, ir::ir_sample_data)
x2 <-
  ir::ir_subtract(ir::ir_sample_data, ir::ir_sample_data[1, ])

# subtracting a numeric value from an object of class `ir`.
x3 <-
  ir::ir_subtract(ir::ir_sample_data, 20)

# subtracting a numeric vector from an object of class `ir`.
x4 <-
  ir::ir_subtract(
     ir::ir_sample_data,
     seq(from = 0, to = 2, length.out = nrow(ir::ir_sample_data))
  )