# Subsetting `ir` objects ```r ## S3 method for class 'ir' x[i, j, ..., exact = TRUE] ## S3 method for class 'ir' x$i ## S3 method for class 'ir' x[[i, j, ..., exact = TRUE]] ## S3 replacement method for class 'ir' x$i, j, ... <- value ## S3 replacement method for class 'ir' i[j, ..., exact = TRUE] <- value ## S3 replacement method for class 'ir' i[[j, ..., exact = TRUE]] <- value ``` ## Arguments - `x`: An object of class `ir`. - `i, j`: Row and column indices. If `j` is omitted, `i` is used as column index. - `...`: Ignored. - `exact`: Ignored, with a warning. - `value`: A value to store in a row, column, range or cell. Tibbles are stricter than data frames in what is accepted here. ## Returns If the subsetting operation preserves a valid `spectra` column (see `ir()`), an object of class `ir` with accordingly subsetted rows or columns. Else a `tibble::tbl_df()` or vector. ## Examples ```r # subsetting rows ir_sample_data[1, ] ir_sample_data[10:15, ] ir_sample_data[ir_sample_data$sample_type == "office paper", ] # subsetting columns ir_sample_data[, "spectra"] ir_sample_data[["spectra"]] ir_sample_data$spectra # not explicitly selecting the spectra column drops the ir class class(ir_sample_data[, 1]) class(ir_sample_data[, "spectra"]) # subsetting values ir_sample_data[, 1] # drops the ir class ir_sample_data[, c("id_sample", "spectra")] ir_sample_data$id_sample ir_sample_data[[1, 1]] # setting and replacing columns x <- ir::ir_sample_data x$a <- 3 x[, "a"] <- 4 x$sample_type <- "a" x[[1]] <- rev(x[[1]]) # deleting the spectra column drops the ir class x$spectra <- NULL class(x) # setting and replacing rows x <- ir::ir_sample_data x[1, ] <- x[2, ] class(x) # setting invalid values in the spectra column drops the ir class x_replacement <- x[1, ] x_replacement$spectra <- list(1) x[1, ] <- x_replacement class(x) # setting and replacing values x <- ir::ir_sample_data x[[1, 1]] <- 100 # replacing an element in the spectra column by an invalid element drops the # ir class attribute x[[3, "spectra"]] <- list(1) class(x) ```

subsetting function