R语言代码：
data <- read.csv('fanchart.csv',header = T,row.names = 1)
rname <- rownames(data)
data <- ts(data, frequency = 4, start = c(2006, 3))
var <- VAR(data, p = 1, type = "const")
var.prd <- predict(var, n.ahead = 20, ci = 0.95)
fanchart(var.prd,names='G')
axis(1,at=22,labels='what')
最后的图形结果

为什么无法改变坐标轴刻度标签？求大神指导指导