Question

I am trying to create a data.frame where some cells have missing values. Instead of showing NAs, I wonder if there is any way to hide the NAs? What I want essentially is like an ANOVA table as shown below.

 x = rnorm(40)    
 y = rep(1:2, each=20)    
 z = rep(c(1,2,1,2), each=10)  
 model1 = lm(x~y * z)  
 model2 = lm(x~y + z)  
 anova(model1, model2)  

 #Analysis of Variance Table
 #Model 1: x ~ y * z
 #Model 2: x ~ y + z
 #Res.Df    RSS Df Sum of Sq      F Pr(>F)
 #1     36 38.931                           
 #2     37 39.248 -1  -0.31705 0.2932 0.5915

The output is above. If you try to access those blank cells, you will get NAs

 anova(model1, model2)[1,4]
 #[1] NA

Thanks in advance!!

Answer 1

print.anova works by using the na.print option of print.default, like this:

> x <- matrix(c(101:111/100, NA), nrow=3)
> print(x, na.print="")
     [,1] [,2] [,3] [,4]
[1,] 1.01 1.04 1.07 1.10
[2,] 1.02 1.05 1.08 1.11
[3,] 1.03 1.06 1.09     

However, this only works for matrices, not for data frames.

For data frames, the suggestion of replacing the NA’s with “” is good, but loses the usual printing of digits; you can do so by using format.data.frame before replacement. Read the print.data.frame function for more details. Doing it this way, you can also replace with NA and then use the na.print option, as above.

> y <- as.data.frame(x)
> m <- as.matrix(format.data.frame(y, digits = NULL, na.encode = FALSE))
> m[is.na(y)] <- NA
> print(m, na.print="", quote=FALSE)
  V1   V2   V3   V4  
1 1.01 1.04 1.07 1.10
2 1.02 1.05 1.08 1.11
3 1.03 1.06 1.09   

See how the digits in the fourth column line up? Compare to this.

> z <- y
> z[is.na(z)] <- ""
> print(z)
    V1   V2   V3   V4
1 1.01 1.04 1.07  1.1
2 1.02 1.05 1.08 1.11
3 1.03 1.06 1.09