Replace column names in kable/R markdown

My data frame has ugly column names, but when displaying the table in my report, I want to their "real" names including special characters '(', new lines, greek letters, repeated names, etc.

Is there an easy way of replacing the names in knitr to allow such formatting?

Proposed solution

What I have tried to do is suppress the printing of the data frame names and use add_header_above for better names and names that span several columns. Some advice I've seen says to use:

x <- kable(df)
gsub("<thead>.*</thead>", "", x)

to remove the column names. That's fine, but the issue is that when I subsequently add_header_above, the original column names come back. If I use col.names=rep('',times=ncol(d.df)) in kable(...) the names are gone but the row remains, leaving a gap between my new column names and the table body. Here's a code chunk to illustrate:

```{r functions,echo=T}
drawTable <- function(d.df,caption='Given',hdr.above){
require(knitr)
require(kableExtra)
require(dplyr)

hdr.2 <- rep(c('Value','Rank'),times=ncol(d.df)/2)
x <- knitr::kable(d.df,format='latex',align='c',
  col.names=rep('',times=ncol(d.df))) %>%     
kable_styling(bootstrap_options=c('striped','hover',
  'condensed','responsive'),position='center',
   font_size = 9,full_width=F)

x %>% add_header_above(hdr.2) %>%
  add_header_above(hdr.above)
}
```

```{r}
df <- data.frame(A=c(1,2),B=c(4,2),C=c(3,4),D=c(8,7))
hdr.above <- c('A2','B2','C2','D2')
drawTable(df,hdr.above = hdr.above)
```

I am not sure where you got the advice to replace rownames, but it seems excessively complex. It is much easier just to use the built-in col.names argument within kable. This solution works for both HTML and LaTeX outputs:

---
output:
  pdf_document: default
  html_document: default
---
```{r functions,echo=T}
require(knitr)

df <- data.frame(A=c(1,2),B=c(4,2),C=c(3,4),D=c(8,7))
knitr::kable(df, 
             col.names = c("Space in name",
                           "(Special Characters)",
                           "$\\delta{m}_1$",
                           "Space in name"))

```

PDF output: