用不同水平的刻度线绘制

Question

我想知道是否可以将刻度线标签放在两个不同的水平线上以避免标签之间的重叠。 例如这里：

a=c[1:10] 
b=c("January","February","March","April","May","June","July","August","September","October") 
barplot(a,space=0,axes=F) 
ticks=a 
axis(side=1, at =ticks, labels=b) 

Answer 1

，你可以尝试以下方法：

a=1:10 
b=c("January","February","March","April","May","June","July","August","September","October") 
barplot(a,space=0,axes=F) 
ticks=a 

# indices of even ticks 
idx <- seq(2, length(ticks), 2) 

# b2 only contains the odd labels. 
b2 <- b 
# Empty space so a small line gets drawn at omitted labels 
b2[idx] <- "" 

# draw odd labels 
axis(side=1, at =ticks, labels=b2, line = 0) 
# same command for even ticks, lwd = 0 suppresses drawing the x-axis twice 
axis(side=1, at =ticks[idx], labels=b[idx], line = 1, lwd = 0) 

这基本上通过在奇数位置先绘制标签，然后在偶数位置绘制标签，但由于略低规避重叠line = 1。

Answer 2

您可以尝试拨打两个axis电话，一个用于奇数月份，另一个用于偶数月份，并将它们放在不同的line上。第一个axis调用只是绘制没有标签的刻度。

a=1:10 
a_even <- a[a %% 2==0] 
a_odd <- a[a %% 2==1] 
b=c("January","February","March","April","May","June","July","August","September","October") 
barplot(a,space=0,axes=F) 
ticks=a 
axis(side=1, at =ticks, labels=FALSE,line = 1) 
axis(side=1, at =ticks[a_odd], labels=b[a_odd],line = 1,tick = FALSE) 
axis(side=1, at =ticks[a_even], labels=b[a_even],line = 2,tick = FALSE)