This function converts pollution running averages in the original units (ppb, µg/m³, etc) to IMECA

convert_to_imeca(value, pollutant, showWarnings = TRUE)

## Arguments

value a numeric vector of values to convert to IMECAs. Note that the concentration of pollutants can be measured in different ways, for NO2, and O3 a 1 hour average is used, for CO, an 8 hour average, and for SO2, PM10 and PM25 a 24 hour average is used. type of pollutant. A vector of one or more of the following options: "SO2" - Sulfur Dioxide - ppb (24 hour average) "CO" - Carbon Monoxide - ppm (8 hour average) "NO2" - Nitrogen Dioxide - pbb (1 hour average) "O3" - Ozone ppb (1 hour average) "PM10" - Particulate matter 10 micrometers or less (24 hour average) "PM25" - Particulate matter 2.5 micrometers or less (24 hour average) deprecated; you can use the function suppressWarnings instead.

## Value

A vector containing the converted value in IMECAs

## Details

Air quality in Mexico City is reported in IMECAs (Índice Metropolitano de la Calidad del Aire), a dimensionless scale where all pollutants can be compared.

Note that each pollutant has different averaging periods (see the arguments section). Because of rounding error results may be off by a couple of points.

For the formulas on how to convert visit: AVISO POR EL QUE SE DA A CONOCER EL PROYECTO DE NORMA AMBIENTAL PARA EL DISTRITO FEDERAL

Other convert functions: convert_to_index

## Examples

## IMECA is a dimensionless scale that allows for the comparison of
## different pollutants
convert_to_imeca(157, "O3")#>  153convert_to_imeca(c(450, 350, 250), rep("NO2", 3))#>  155 132 110## Since this is PM10 the 80 is supposed to be the 24 hour average
convert_to_imeca(80, "PM10")#>  102
## warning about recycling elements in a vector
convert_to_imeca(c(157, 200), "O3")#> Warning: The vectors are of unequal length. Recycling elements of the shorter vector to match the longer vector.#>  153 196
convert_to_imeca(67, "O3")#>  48convert_to_imeca(77, "O3")#>  63convert_to_imeca(205, "O3")#>  201convert_to_imeca(72, "O3")#>  53convert_to_imeca(98, "O3")#>  103