[R] depth of labels of axis

[Jinsong Zhao]

Hi there,

With the following code,

plot(1:5, xaxt = "n")
axis(1, at = 1:5, labels = c(expression(E[g]), "E", expression(E[j]), 
"E", expression(E[t])))

you may notice that the "E" within labels of axis(1) are not at the same 
depth. So the vision of axis(1) labels is something like wave.

Is there a possible way to typeset the labels so that they are have the 
same depth?

Any suggestions will be really appreciated. Thanks in advance.

Best regards,
Jinsong