R GraphicsLesson 26Free preview

R Scatterplot

This lesson is part of R · All levels

Summary

This study reviews the Scatterplot (scatter diagram) used to study the relationship or correlation between two continuous quantitative variables. Developers will learn how to draw scatterplots, interpret the direction of positive/negative correlation, as well as add linear regression trend lines using the abline() function.

Key points

Scatterplot maps the pair of coordinate dots (x, y) to see the data correlation
The pattern of dots that tilt up to the right shows a positive correlation
The 'cor(x, y)' function calculates the coefficient of mathematical correlation
The 'abline(lm(y ~ x))' function draws the best linear regression of the trend across data dots

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