# R绘图基础（4）符号与线形

```> pchShow <- + function(extras = c("*",".", "o","O","0","+","-","|","%","#"), + cex = 3, ## good for both .Device=="postscript" and "x11" + col = "red3", bg = "gold", coltext = "brown", cextext = 1.2, + main = paste("plot symbols : points (... pch = *, cex =", + cex,")")) + { + nex <- length(extras) + np <- 26 + nex + ipch <- 0:(np-1) + k <- floor(sqrt(np)) + dd <- c(-1,1)/2 + rx <- dd + range(ix <- ipch %/% k) + ry <- dd + range(iy <- 3 + (k-1)- ipch %% k) + pch <- as.list(ipch) # list with integers & strings + if(nex > 0) pch[26+ 1:nex] <- as.list(extras) + plot(rx, ry, type="n", axes = FALSE, xlab = "", ylab = "", + main = main) + abline(v = ix, h = iy, col = "lightgray", lty = "dotted") + for(i in 1:np) { + pc <- pch[[i]] + ## 'col' symbols with a 'bg'-colored interior (where available) : + points(ix[i], iy[i], pch = pc, col = col, bg = bg, cex = cex) + if(cextext > 0) + text(ix[i] - 0.3, iy[i], pc, col = coltext, cex = cextext) + } + } > > pchShow()```

• 本文由 发表
• 转载请务必保留本文链接：https://www.plob.org/article/10127.html