function (pollutant = c("o3", "no2", "so2", "co", "nmvoc", "pm10", 
    "pm1", "cpc", "temp", "prec", "rad"), stations = c("Bern-Bollwerk", 
    "Lausanne-César-Roux", "Lugano-Università", "Zürich-Kaserne", 
    "Basel-Binningen", "Dübendorf-Empa", "Härkingen-A1", "Sion-Aéroport-A9", 
    "Magadino-Cadenazzo", "Payerne", "Tänikon", "Lägeren", 
    "Chaumont", "Rigi-Seebodenalp", "Davos-Seehornwald", "Jungfraujoch"), 
    interval = c("hourly", "daily"), period = c("day", "week", 
        "month", "free"), from = NULL, to = NULL) 
{
    schadstoff <- list(o3 = "Ozone (O3)", no2 = "Nitrogen dioxide (NO2)", 
        so2 = "Sulfur dioxide (SO2)", co = "Carbon monoxide (CO)", 
        nmvoc = "Non-methane volatile organic compounds (NMVOC)", 
        pm10 = "Particulate matter (PM10)", pm1 = "Particulate matter (PM1)", 
        cpc = "Particulate number concentration (CPC)", temp = "Temperature (TEMP)", 
        prec = "Precipitation (PREC)", rad = "Global radiation (RAD)")
    stationsliste <- c("Bern-Bollwerk", "Lausanne-César-Roux", 
        "Lugano-Università", "Zürich-Kaserne", "Basel-Binningen", 
        "Dübendorf-Empa", "Härkingen-A1", "Sion-Aéroport-A9", 
        "Magadino-Cadenazzo", "Payerne", "Tänikon", "Lägeren", 
        "Chaumont", "Rigi-Seebodenalp", "Davos-Seehornwald", 
        "Jungfraujoch")
    datentyp <- list(hourly = "stunden", daily = "tag")
    zeitraum <- list(day = "1tag", week = "1woche", month = "1monat", 
        free = "frei")
    pollutant <- match.arg(pollutant)
    stations <- unlist(stations)
    if (is.numeric(stations)) {
        stations <- stationsliste[stations]
    }
    else {
        stations <- match.arg(stations, several.ok = TRUE)
    }
    interval <- match.arg(interval)
    period <- match.arg(period)
    if (period == "free") {
        from <- format(as.Date(from), "%d.%m.%Y")
        to <- format(as.Date(to), "%d.%m.%Y")
    }
    params <- c(abfrageflag = "true", station = "1", nach = "schadstoff", 
        ausgabe = "csv", submit = "Query")
    params <- c(params, schadstoff = match(pollutant, names(schadstoff)))
    for (i in seq(along = schadstoff)) {
        params <- c(params, `schadstoffsliste[]` = i)
    }
    for (i in seq(along = stations)) {
        params <- c(params, `stationsliste[]` = match(stations[i], 
            stationsliste))
    }
    params <- c(params, datentyp = datentyp[[interval]])
    params <- c(params, zeitraum = zeitraum[[period]])
    if (period == "free") {
        params <- c(params, von = from)
        params <- c(params, bis = to)
    }
    url <- "https://bafu.meteotest.ch/nabel/index.php/ausgabe/index/english"
    paramstr <- paste(names(params), params, sep = "=", collapse = "&")
    doc <- readLines(paste(url, paramstr, sep = "?"), encoding = "latin1")
    doc <- enc2utf8(doc)
    head <- readLines(textConnection(doc), n = 30)
    skip <- grep("Date/time;", head) - 1
    dat <- read.table(textConnection(doc), sep = ";", skip = skip, 
        header = TRUE, fill = TRUE, as.is = TRUE, check.names = FALSE)
    dat <- dat[dat[, 1] != "0", ]
    names(dat)[1] <- "datetime"
    sta <- names(dat)[-1]
    if (interval == "hourly") {
        dat$datetime <- as.POSIXct(strptime(dat$datetime, format = "%d.%m.%Y %H:%M"))
    }
    else {
        dat$datetime <- as.POSIXct(strptime(dat$datetime, format = "%d.%m.%Y"))
    }
    dat <- reshape(dat, direction = "long", timevar = "station", 
        varying = list(sta))
    names(dat)[2] <- "station"
    names(dat)[3] <- "measurement"
    dat$id <- NULL
    dat$station <- factor(dat$station, labels = sta)
    ylabs <- list(o3 = expression(paste("Ozone (O3, in ", mu, 
        "g/m", {
        }^3, ")")), no2 = expression(paste("Nitrogen dioxide (NO2, in ", 
        mu, "g/m", {
        }^3, ")")), so2 = expression(paste("Sulfur dioxide (SO2, in ", 
        mu, "g/m", {
        }^3, ")")), co = expression(paste("Carbon monoxide (CO, in mg/m", 
        {
        }^3, ")")), nmvoc = "Non-methane volatile organic compounds (NMVOC, in ppm)", 
        pm10 = expression(paste("Particulate matter (PM10, in ", 
            mu, "g/m", {
            }^3, ")")), pm1 = expression(paste("Particulate matter (PM1, in ", 
            mu, "g/m", {
            }^3, ")")), cpc = expression(paste("Particulate number concentration (CPC, in 1/cm", 
            {
            }^3), ")"), temp = "Temperature (TEMP, in °C)", 
        prec = "Precipitation (PREC, in mm)", rad = expression(paste("Global radiation (RAD, in W/m", 
            {
            }^2, ")")))
    pl <- xyplot(measurement ~ datetime, dat, groups = station, 
        type = c("l"), auto.key = list(space = "right", points = FALSE, 
            lines = TRUE), xlab = "date/time (Europe/Zurich)", 
        ylab = ylabs[[pollutant]])
    print(pl)
}
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<environment: namespace:nabel>