Tidy allodb::equations in advance, not in new_equaions()

[maurolepore]

The body of new_equations() starts cleaning up
the allodb::equations. If any such cleaning is
necessary, then it would be best to do it once
when we create allodb::equations rather than
every time a user calls new_equations(). This
should also help simplify new_equations(),
which already seems to do too much work.

Here is a piece of code that could go elsewhere

  ## open the equation table and get it in the right format ####
  equations_orig <- allodb::equations
  colnames(equations_orig) <- tolower(colnames(equations_orig))
  new_equations <- equations_orig

Here are the columns we could lowercase:

setdiff(
  names(allodb::equations),
  tolower(names(allodb::equations))
)
#> [1] "mat_C"           "min.temp_C"      "max.temp_C"      "dbh_unit_CF"    
#> [5] "output_units_CF"

^{Created on 2021-10-09 by the reprex package (v2.0.1)}

--

Another piece of code that could go elsewhere

  suppressWarnings(new_equations$dbh_min_cm <-
    as.numeric(new_equations$dbh_min_cm))
  suppressWarnings(new_equations$dbh_max_cm <-
    as.numeric(new_equations$dbh_max_cm))
  suppressWarnings(new_equations$sample_size <-
    as.numeric(new_equations$sample_size))
  suppressWarnings(new_equations$dbh_unit_cf <-
    as.numeric(new_equations$dbh_unit_cf))
  suppressWarnings(new_equations$output_units_cf <-
    as.numeric(new_equations$output_units_cf))

This could be also done where we create allodb::equations, and maybe replaced by a simpler approach, e.g.:

# Setup
equations <- allodb::equations
names(equations) <- tolower(names(equations))

# This replaces the code above
to_numeric <- c("dbh_min_cm", "dbh_max_cm", "sample_size", "dbh_unit_cf", "output_units_cf")
equations[to_numeric] <- lapply(equations[to_numeric], \(x) suppressWarnings(as.numeric(x)))

unlist(lapply(equations[to_numeric], typeof))
#>      dbh_min_cm      dbh_max_cm     sample_size     dbh_unit_cf output_units_cf 
#>        "double"        "double"        "double"        "double"        "double"

^{Created on 2021-10-09 by the reprex package (v2.0.1)}