How to have a new line in a `bquote` expression used with `text`?
data-visualization, plotmath, r
Solution
One of the errors was noted above in my comment to the questioner. R expressions get parsed so they need to be syntactically valid. Since "==" is a two-argument function it cannot be the final item in an expression. The `phantom` function serves as a placeholder that is non-printing. Could also have been an empty character value (`""`). Since there was no "outside" value that needed to be evaluated, I just used `expression()` rather than `bquote()` for the first argument in the expression list.
(Note: that expressions in R behave as lists so that `c()` succeeds in appending language items to a single element expression and `list()` is not needed, and in fact was harmful in this situation. There is another subtlety in that `bquote` does not return an "expression"-classed result but rather a "call". It may need to be wrapped with `as.expression` if a true "expression" is needed as was the case here. I've seen R savants use an `lapply( . , as.expression)` to return an expression list in similar situations.)
The other one was more a semantic error than a syntactic one. You need to give an explicit y location for the second `bquote` expression. Pretty much all of the important arguments of text are vector-capable but there doesn't appear to be implicit up-(or down-)indexing for the y values:
test <- c(1, 2, 3, 4, 4.5, 3.5, 5.6)
test2 <- 0.033111111
lines <- c( expression(Qua[0.99] == phantom(0)) ,
bquote(.(round(test2,4)))
)
plot(test,c(1:length(test)))
segments(4,0,4,23,col="red",lwd=2)
text(5, c(4.5, 4), labels =lines ,col="red", cex = 1.4)
I have used the `atop` suggestion myself in the past, even suggesting it on Rhelp, but I think the approach above generalizes better to three or more expressions and allows more control over positioning. `atop` also silently reduces font sizes, so if you went the nested atop route for a three expression task, it might need to be `atop( atop(..., ...), atop(..., phantom() )` to keep the sizes uniform.
If you include `adj=0` in `text`-call arguments list you get left justification. Tested in the code for the code above.
Problem
I want to have a new line in my `bquote` envrionment, how can I do this? my code: ``` test<-c(1,2,3,4,4.5,3.5,5.6) test2<-0.033111111 plot(test,c(1:length(test))) segments(4,0,4,23,col="red",lwd=2) text(5, 4.5, labels = bquote(Qua[0.99] == .(round(test2,4))),col="red", cex = 1.4) ``` And I want to have a new line after the equal sign, so this should give: ``` VaR_0.99 = 0.03311 and not VaR_0.99 = 0.03311 ``` I tried it with lines, but it did not work: ``` test<-c(1,2,3,4,4.5,3.5,5.6) test2<-0.033111111 lines<-list(bquote(Qua[0.99] == ),bquote(.(round(test2,4)))) plot(test,c(1:length(test))) segments(4,0,4,23,col="red",lwd=2) text(5, 4.5, labels =lines ,col="red", cex = 1.4) ```