*
* Analysis and graphics of Anscombe's data, pp 50-52
*
all 11
open data anscombe.dat
data(format=prn,org=columns)
*
* SPGRAPH (Special Purpose GRAPH) is used for a variety of specialty graphs.
* Here, it is used to make a 2x2 array of graphs. HFIELDS and VFIELDS specify the
* number of horizontal and vertical fields on the page. The SCATTER instructions
* then fill in the panes (by default, working down by columns, which is why this
* does the third before the second). The SPGRAPH(DONE) instruction at the end
* means that the full page of graphs is finished and can be displayed.
*
* The LINES option on the SCATTER instruction is used to draw straight lines.
* lines=%beta draws a line with intercept %beta(1) and slope %beta(2).
*
spgraph(hfields=2,vfields=2,footer="Figure 3.1 Anscombe's Quartet: Bivariate Scatterplots")
linreg yone
# constant xone
scatter(hlabel="X1",vlabel="Y1",lines=%beta)
# xone yone
linreg ythree
# constant xthree
scatter(hlabel="X3",vlabel="Y3",lines=%beta)
# xthree ythree
linreg ytwo
# constant xtwo
scatter(hlabel="X2",vlabel="Y2",lines=%beta)
# xtwo ytwo
linreg yfour
# constant xfour
scatter(hlabel="X4",vlabel="Y4",lines=%beta)
# xfour yfour
spgraph(done)