Formula Constructor

This function constructs a formula from a data frame given the locations of the response and other variables. It is useful for long or repetitive formulas.

Usage

makeform(data, ycol, xcol, zcol, FUN, maxy = 20, extra)

Arguments

data

The data frame or matrix for which the formula is to be contructed,

ycol

The locations (or names) of the response variables in data.

xcol

The locations (or names) of the explanatory variables in data.

zcol

The locations (or names) of the conditioning variables in data; for use in the vegan package.

FUN

A function to apply to the response.

maxy

The number of multivariate responses before abbreviated notation is used. see examples below.

extra

Extra term(s) for the RHS of the formula.

Details

makeform constructs a formula and is useful for long and/or repetitive formulae. See examples below.

Value

Returns a formula.

Examples

data(spider)
makeform(spider,1,13:18)
#> arct.lute ~ water + sand + moss + reft + twigs + herbs
#> <environment: 0x555b9aa03148>
# arct.lute ~ water + sand + moss + reft + twigs + herbs

makeform(spider,1:12,13:18)
#> cbind(arct.lute, pard.lugu, zora.spin, pard.nigr, pard.pull, 
#>     aulo.albi, troc.terr, alop.cune, pard.mont, alop.acce, alop.fabr, 
#>     arct.peri) ~ water + sand + moss + reft + twigs + herbs
#> <environment: 0x555b9a920938>
# cbind(arct.lute, pard.lugu, zora.spin, pard.nigr, pard.pull, 
# aulo.albi, troc.terr, alop.cune, pard.mont, alop.acce, alop.fabr, 
# arct.peri) ~ water + sand + moss + reft + twigs + herbs

makeform(spider,1:12,13:15,16:18)
#> cbind(arct.lute, pard.lugu, zora.spin, pard.nigr, pard.pull, 
#>     aulo.albi, troc.terr, alop.cune, pard.mont, alop.acce, alop.fabr, 
#>     arct.peri) ~ water + sand + moss + Condition(reft + twigs + 
#>     herbs)
#> <environment: 0x555b9a7a5c00>
# cbind(arct.lute, pard.lugu, zora.spin, pard.nigr, pard.pull, 
# aulo.albi, troc.terr, alop.cune, pard.mont, alop.acce, alop.fabr, 
# arct.peri) ~ water + sand + moss + Condition(reft + twigs + herbs)

makeform(spider,1:12,13:15,maxy=6)
#> as.matrix(spider[, 1:12]) ~ water + sand + moss
#> <environment: 0x555b9a6ac260>
# as.matrix(spider[, 1:12]) ~ water + sand + moss

makeform(spider,1:3,13:15,FUN=sqrt)
#> sqrt(cbind(arct.lute, pard.lugu, zora.spin)) ~ water + sand + 
#>     moss
#> <environment: 0x555b9a4322e8>
# sqrt(cbind(arct.lute, pard.lugu, zora.spin)) ~ water + sand + moss

makeform(spider,1:3,13:15,FUN=sqrt,extra="I(water^2)+")
#> sqrt(cbind(arct.lute, pard.lugu, zora.spin)) ~ I(water^2) + water + 
#>     sand + moss
#> <environment: 0x555b9a2590b8>
# sqrt(cbind(arct.lute, pard.lugu, zora.spin)) ~ I(water^2) + water + 
# sand + moss