Stripchart R | R Strip Chart using stripchart() function - r - learn r - r programming
- Strip charts can be created using the stripchart() function in R programming language.
- This function takes in a numeric vector or a list of numeric vectors, drawing a strip chart for each vector.
r programming strip chart
Example 1: Strip chart of daily air quality
> str(airquality)
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp : int 67 72 74 62 56 66 65 59 61 69 ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
- Let us make a strip chart for the ozone readings.
stripchart(airquality$Ozone)
- We can see that the data is mostly cluttered below 50 with one falling outside 150.
- We can pass in additional parameters to control the way our plot looks.
- You can read about them in the help section ?stripchart.
- Some of the frequently used ones are, main-to give the title, xlab and ylab-to provide labels for the axes, method-to specify the way coincident points are plotted like stacked or jitter, col-to define color etc.
- Additionally, with the argument vertical=TRUE we can plot it vertically and with pch we can specify the plotting character (square by default).
- Some values of pch are 0 for square, 1 for circle, 2 for triangle etc.
- You can see the full list in the help section
?points.
Example 2: Strip chart of airquality using jitter
stripchart(airquality$Ozone,
main="Mean ozone in parts per billion at Roosevelt Island",
xlab="Parts Per Billion",
ylab="Ozone",
method="jitter",
col="orange",
pch=1
)
Multiple Strip Charts
- We can draw multiple strip charts in a single plot, by passing in a list of numeric vectors.
- Let us consider the Temp field of airquality dataset.
- Let us also generate normal distribution with the same mean and standard deviation and plot them side by side for comparison.
# prepare the data
temp <- airquality$Temp
# gererate normal distribution with same mean and sd
tempNorm <- rnorm(200,mean=mean(temp, na.rm=TRUE), sd = sd(temp, na.rm=TRUE))
# make a list
x <- list("temp"=temp, "norm"=tempNorm)
- Now we us make 2 stripcharts with this list.
stripchart(x,
main="Multiple stripchart for comparision",
xlab="Degree Fahrenheit",
ylab="Temperature",
method="jitter",
col=c("orange","red"),
pch=16
)
Strip Chart from Formula
- The function stripchart() can also take in formulas of the form y~x where, y is a numeric vector which is grouped according to the value of x.
- For example, in our dataset airquality, the Temp can be our numeric vector.
- Month can be our grouping variable, so that we get the strip chart for each month separately.
- In our dataset, month is in the form of number (1=January, 2-Febuary and so on).
stripchart(Temp~Month,
data=airquality,
main="Different strip chart for each month",
xlab="Months",
ylab="Temperature",
col="brown3",
group.names=c("May","June","July","August","September"),
vertical=TRUE,
pch=16
)
