Using R for Introductory Statistics : John Verzani

Appendix D 358A device is set up with a certain size given by din=. A figure’s size is given by thegraphical parameter fin=. The figure is made up of its margins and the plot region. Theseare stored under mai= and pin=.For example,> par("din","fin","pin","mai”)$din# device size[1] 6.995 6.996$fin# figure size[1] 6.995 6.996$pin# plot size[1] 6.133 5.717$mai# margin sizes[1] 0.7088 0.5698 0.5698 0.2919The first three specify the sizes in inches for width and height. As margins may benonsymmetric, there are four values specified: the bottom, left, top, and right.The values add up as shown by> .5698+.2919 +6.133 # widths[1] 6.995> .7088+.5698 +5.717 # heights[1] 6.996The margins can also be specified by the number of lines of text that can be printed usingmar=. The actual size is relative to the current point size of the text. The argument plt=can specify the plot region in terms of the device size.These areas are usually set up for us when the plot device is. At this point, the overallwidth and height are given, and R makes the necessary computations for the margins. Ifwe are unsatisfied with the defaults, we can override the calculated values. If the marginsor space for the main graphic are made too small, an error message will be given.Multi-graphic figuresIn a few examples in this text, more than one graphic is plotted on the same figure. Forexample, when we plotted the diagnostic plots after fitting a linear model, four graphicswere returned. These can be seen one after another, or can be forced to show up all fourat once if the graphic parameter mfrow= is set to c(2,2).The parameter mfrow= stores two values as a vector. A value of c(3,2) says to split thefigure into six equal pieces, with three rows and two columns. The default is c (1,1).Figures are filled in row by row. Use mf col= to fill in column by column. To advance tothe next area to draw a graphic, we can use a high-level plot command or the functionplot. new ().The f ig= graphical parameter controls the amount of the current figure the nextgraphic will use. By default, this is set to c (0,1,0,1), indicating the whole figure. The firsttwo numbers are the x value, and the second two are y. They refer to the lower left of thefigure. For example, a value like c(0,1/2,1/2,1) will use the upper-left part of the figure.The parameter new= should be set to TRUE to add to the existing figure with a high-levelplot command.