How does one set up logical functions?
On Tue, May 7, 2013 at 11:06 AM, Gabor Grothendieck
<ggrothendieck at gmail.com> wrote:
On Tue, May 7, 2013 at 10:02 AM, Neotropical bat risk assessments <neotropical.bats at gmail.com> wrote:
Hi all, I am trying to set up logical function(s) to deal with two adjustments to a blood glucose value. I have been dinking around in Excel and assume this will be much easier in R. DF is date-time, BG value in mg/dL,test strip 4/3/13 19:20 105 Aviva-491350 4/4/13 21:03 74 Aviva-491350 4/6/13 17:40 81 Aviva-491640 4/6/13 17:40 82 Aviva-491350 4/6/13 22:48 106 Aviva-491640 4/6/13 22:48 102 Aviva-491350 4/7/13 5:32 87 Aviva-491350 4/7/13 5:32 103 Aviva-491640 What I need are the high and low ranges based on "acceptable" standards of the measured values. The logical expressions need to be IF BG =>100 then "High limit" would = (BG+(BG*.15)) IF BG =>100 then "Low limit" would = (BG-(BG*.15)) and IF BG <100 then "High limit" would = (BG+15) IF BG <100 then "Low limit" would = (BG-15) The standards are written as: 95% of the individual glucose results shall fall within ?15 mg/dL of the reference results at glucose concentrations less than 100 mg/dL and within ?15% at glucose concentrations greater than or equal to 100 mg/dL. Then I need to plot the measured value and also show the high & low "acceptable" values.
Here it is using gglot2:
Here it is again with some fixes and also reading the input data so
its all self contained:
library(ggplot2)
library(gridExtra)
Lines <- "date time BG test_strip
4/3/13 19:20 105 Aviva-491350
4/4/13 21:03 74 Aviva-491350
4/6/13 17:40 81 Aviva-491640
4/6/13 17:40 82 Aviva-491350
4/6/13 22:48 106 Aviva-491640
4/6/13 22:48 102 Aviva-491350
4/7/13 5:32 87 Aviva-491350
4/7/13 5:32 103 Aviva-491640"
DF <- read.table(text = Lines, header = TRUE)
DF2 <- transform(DF,
datetime = as.POSIXct(paste(date, time), format = "%m/%d/%y %H:%M"),
lower = ifelse(BG < 100, BG - 15, BG * 0.85),
upper = ifelse(BG < 100, BG + 15, BG * 1.15))
ggplot(DF2, aes(datetime, BG)) +
geom_point() +
geom_line() +
geom_smooth(aes(ymin = lower, ymax = upper), stat = "identity") +
geom_linerange(aes(ymin = lower, ymax = upper)) +
annotation_custom(tableGrob(DF2, gp = gpar(cex = 0.5)), ymin = 120) +
coord_cartesian(ylim = c(60, 150)) +
xlab("") +
ylab("Blood Glucose") +
ggtitle("Blood Glucose Levels")
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