R/test-fns.R

In osmplotr: Bespoke Images of 'OpenStreetMap' Data

# ---------  lengths of vectors
test_len1 <- function (a, txt) {

    if (length (a) > 1) {

        warning (paste ("Only the first element of", txt, "will be used"))
        a <- a [1]
    }
    return (a)
}

test_len2 <- function (a, txt) {

    if (length (a) > 2) {

        warning (paste ("Only the first two elements of", txt, "will be used"))
        a <- a [1:2]
    }
    return (a)
}

# ---------  object classes
test_numeric <- function (a, txt, value) {

    if (!is.numeric (a)) {

        if (length (value) == 1)
            vstr <- "value"
        else
            vstr <- "values"
        w <- simpleWarning (paste (txt, "must be numeric; using default", vstr))
        a <- tryCatch(as.numeric (a), warning = function(c) w)
        if (is (a, "warning")) {

            warning (a)
            a <- value
        }
    }
    return (a)
}

test_logical <- function (a, txt, value) {

    if (!is.logical (a)) {

        w <- simpleWarning (paste (txt, "must be logical; using default"))
        if (is.na (as.logical (a))) {

            warning (w)
            a <- value
        }
    }
    return (a)
}

# ---------  object values
test_pos <- function (a, txt, value) {

    if (a < 0) {

        warning (paste (txt, "must be positive; using default value"))
        a <- 3
    }
    return (a)
}

test_range <- function (a, txt, rng, value) {

    if (any (a < rng [1]) | any (a > rng [2])) {

        if (length (value) == 1)
            vstr <- "value"
        else
            vstr <- "values"
        warning (paste0 (txt, " not in [", rng [1], ",", rng [2],
                         "]; using default ", vstr))
        a <- value
    }
    return (a)
}