EVOLUTION-MANAGER

Edit File: measurement_units_in_R.R

## ----echo=FALSE--------------------------------------------------------------- knitr::opts_chunk$set(collapse = TRUE) ## ----------------------------------------------------------------------------- temp_data = subset(read.table("647_Global_Temperature_Data_File.txt", header=TRUE)[1:2], Year >= 1960) temp_data$date = as.Date(paste0(temp_data$Year, "-01-01")) temp_data$time = as.POSIXct(temp_data$date) Sys.setenv(TZ="UTC") head(temp_data, 3) year_duration = diff(temp_data$date) mean(year_duration) ## ----------------------------------------------------------------------------- year_duration %*% rep(1, length(year_duration)) / length(year_duration) ## ----------------------------------------------------------------------------- coef(lm(Annual_Mean ~ date, temp_data)) coef(lm(Annual_Mean ~ time, temp_data)) ## ---- eval=requireNamespace("measurements", quietly=TRUE)--------------------- library(measurements) conv_unit(2.54, "cm", "inch") conv_unit(c("101 44.32","3 19.453"), "deg_dec_min", "deg_min_sec") conv_unit(10, "cm_per_sec", "km_per_day") ## ---- eval=requireNamespace("measurements", quietly=TRUE)--------------------- names(conv_unit_options) conv_unit_options$volume ## ---- eval=requireNamespace("measurements", quietly=TRUE)--------------------- conv_dim(x = 100, x_unit = "m", trans = 3, trans_unit = "ft_per_sec", y_unit = "min") ## ---- eval=requireNamespace("NISTunits", quietly=TRUE)------------------------ library(NISTunits) NISTwattPerSqrMeterTOwattPerSqrInch(1:5) ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- library(udunits2) ls(2) ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- ud.is.parseable("m/s") ud.is.parseable("q") ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- ud.are.convertible("m/s", "km/h") ud.are.convertible("m/s", "s") ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- ud.convert(1:3, "m/s", "km/h") ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- ud.get.name("kg") ud.get.symbol("kilogram") ud.set.encoding("utf8") ## ---- eval=requireNamespace("udunits2", quietly=TRUE)------------------------- m100_a = paste(rep("m", 100), collapse = "*") dm100_b = "dm^100" ud.is.parseable(m100_a) ud.is.parseable(dm100_b) ud.are.convertible(m100_a, dm100_b) ## ----------------------------------------------------------------------------- library(units) x = set_units(1:5, m/s) str(x) ## ----------------------------------------------------------------------------- set_units(1:3, m/s^2) ## ----------------------------------------------------------------------------- x = set_units(1:3, m/s) x + 2 * x ## ----------------------------------------------------------------------------- (x = set_units(x, cm/s)) as.numeric(x) ## ----------------------------------------------------------------------------- y = set_units(1:3, km/h) x + y y + x x == y c(y, x) ## ----------------------------------------------------------------------------- x * y x^3 ## ----------------------------------------------------------------------------- e = try(z <- x + x * y) attr(e, "condition")[[1]] ## ----------------------------------------------------------------------------- methods(class = "units") ## ----------------------------------------------------------------------------- a = set_units(1:10, m/s) b = set_units(1:10, h) a * b ustr1 = paste(rep("m", 101), collapse = "*") ustr2 = "dm^100" as_units(ustr1) / as_units(ustr2) ## ----------------------------------------------------------------------------- set_units(1, m^5/s^4) ## ----------------------------------------------------------------------------- as_units("m2 s-1") deparse_unit(set_units(1, m^2*s^-1)) ## ----fig=TRUE, height=3.8, width=7-------------------------------------------- library(units) units_options(negative_power = TRUE) # initialize variables with units: mtcars$consumption = set_units(mtcars$mpg, mi/gallon) # "in" is also a reserved R keyword, and so needs back-quotes: mtcars$displacement = set_units(mtcars$disp, `in`^3) # convert to SI: mtcars$consumption = set_units(mtcars$consumption, km/l) mtcars$displacement = set_units(mtcars$displacement, cm^3) par(mar = par("mar") + c(0, .3, 0, 0)) with(mtcars, plot(1/displacement, 1/consumption)) ## ----fig=TRUE, height=3.8, width=7, eval=requireNamespace("ggforce", quietly=TRUE)---- library(ggforce) if (utils::packageVersion("ggplot2") > "2.2.1") ggplot(mtcars) + geom_point(aes(x = 1/displacement, y = 1/consumption)) ## ----------------------------------------------------------------------------- (dt = diff(Sys.time() + c(0, 1, 1+60, 1+60+3600))) # class difftime (dt.u = as_units(dt)) identical(as_difftime(dt.u), dt) ## ----------------------------------------------------------------------------- (t1 <- as_units(as.POSIXct("2017-08-20 17:03:00"))) (t2 <- as_units(as.POSIXct("2017-08-20 17:03:00"), "hours since 2017-08-20")) (d1 <- as_units(as.Date("2017-08-20"))) as.POSIXct(t1) as.Date(d1)