Exploratory data analysis - Lesson 2

[maribet]

Near the end you compare pm25 for east and west counties in 2 scatterplots. I would have really liked to see this plots side by side with the same SCALE on the Y-AXIS for better visual comparison. Surely there is a way to do this in R?

kind regards Bettina

[WilCrofter]

There are indeed ways to do it in R, as covered in later lessons I believe. For now, plot can be given a ylim argument which sets the Y scale, and plots may be arranged side by side using par("mfrow") or par("mfcol"). For instance:

x <- seq(0, 2*pi, by=.1)
y1 <- cos(x)
y2 <- sin(x)
par(mfrow = c(1,2)) # 1 row of 2 plots
plot(x, y1, ylim=c(-1, 2), main="cos")
plot(x, y2, ylim=c(-1, 2), main="sin")
par(mfrow=c(1,1))

See the help files for par and ylim.

[maribet]

Hi William

Thank you for your answer.

Just wanted to point out, that if you compare data visually, all axes showing the same measure should also have the same scale. Otherwise, if you are not carefull, you might come to wrong conclusions. Especially while doing a “quick and dirty” exploration ;-)

Looking forward to the next lessons!

Bettina Masala Senior Specialist, Computational Statistics GfK T +49 911 395 3747

Von: William R Bauer [mailto:notifications@github.com] Gesendet: Donnerstag, 9. April 2015 03:53 An: swirldev/swirl_courses Cc: Masala, Bettina (GfK SE) Betreff: Re: [swirl_courses] Exploratory data analysis - Lesson 2 (#153)

There are indeed ways to do it in R, as covered in later lessons I believe. For now, plot can be given a ylim argument which sets the Y scale, and plots may be arranged side by side using par("mfrow") or par("mfcol"). For instance:

x <- seq(0, 2*pi, by=.1)

y1 <- cos(x)

y2 <- sin(x)

par(mfrow = c(1,2)) # 1 row of 2 plots

plot(x, y1, ylim=c(-1, 2), main="cos")

plot(x, y2, ylim=c(-1, 2), main="sin")

par(mfrow=c(1,1))

See the help files for par and ylim.

— Reply to this email directly or view it on GitHubhttps://github.com/swirldev/swirl_courses/issues/153#issuecomment-91088830.

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