r - 如何在 ggbiplot 输出中不包含箭头？

Question

我有以下示例数据：

88  0   -3.944  669.8   6.33    637.55  setosa
60  0   -3.477  651.81  6.19    618.55  setosa
4.4 0.001   -2.944  570.7   6.28    544.49  setosa
5000    0.003   -2.585  420.52  5.27    404.39  setosa
116 0.004   -2.365  761.97  6.18    714.59  setosa
300 0.008   -2.079  731.9   5.59    690.57  setosa
70  0.011   -1.942  761.97  6.36    714.59  setosa
121 0.014   -1.852  775.95  5.71    730.59  versicolor
55  0.02    -1.699  681.88  5.64    638.54  versicolor
92.1    0.028   -1.549  653.87  6.25    610.53  versicolor
75  0.041   -1.384  653.83  5.39    614.52  versicolor
20  0.065   -1.187  711.95  6.8 662.56  versicolor
10000   0.075   -1.125  394.48  4.95    380.37  virginica
130 0.085   -1.073  779 7.23    732.63  virginica
400 0.097   -1.012  662.79  5.61    628.52  virginica
99  0.111   -0.954  864.54  9.88    814.14  virginica
400 0.135   -0.87   869.49  7.06    816.06  virginica

我有以下代码：

iris=read.table('file', header=FALSE)
log.ir <- (iris[, 1:6])
ir.species <- iris[, 7]
ir.pca <- prcomp(log.ir, center = TRUE, scale. = TRUE) 
library(devtools)
library(ggbiplot)
g <- ggbiplot(ir.pca, obs.scale = 1, var.scale = 1, groups = ir.species, ellipse = TRUE, circle = FALSE, varname.size=0)
g <- g + scale_color_discrete(name = '')
g <- g + theme(legend.direction = 'horizontal', legend.position = 'top')
print(g)

我的问题是“如何修改它以便不绘制箭头？”

Answer 1

因此，我必须先ggbiplot通过安装devtools并手动更新package::digest，然后才能重现您的示例代码，但var.axes会成功：

g <- ggbiplot(ir.pca, obs.scale = 1, var.scale = 1, groups = ir.species, 
  ellipse = TRUE, circle = FALSE, varname.size=0, var.axes = F)
g <- g + scale_color_discrete(name = '')
g <- g + theme(legend.direction = 'horizontal', legend.position = 'top')