clean up extraneous tibble output

[bob-carpenter]

The current summary output looks like this:

> fit_hmc$summary(c("mu", "tau"))

# A tibble: 2 x 10
  variable    mean  median     sd    mad     q5     q95  rhat ess_bulk ess_tail
  <chr>      <dbl>   <dbl>  <dbl>  <dbl>  <dbl>   <dbl> <dbl>    <dbl>    <dbl>
1 mu       -0.0825 -0.0771 0.0140 0.0158 -0.101 -0.0665  1.97     2.03     18.1
2 tau       8.22    8.15   0.269  0.325   7.88   8.64    2.12     1.87     12.4

It also prints negative numbers in red. I can remove the red negative numbers with a global option:

> options(pillar.neg = FALSE)

I haven't been able to see how to get rid of the other output I consider to be extraneous:

1. the line saying it's a tibble (# A tibble: 2 x 10)
2. the line providing types: (<chr> <dbl> ...)
3. row numbers (1 for mu, 2 for tau)

P.S. This is low priority, especially if it's a huge pain to provide alternative tibble output.

[avehtari]

I would also like to have prettier output. In notebooks I'm now testing using lemon package, which with simple addition to code block options changes the output to look like

It's not a perfect solution as changing, e.g. the width requires additional tricks.

[mjskay]

If someone wants to tackle this a good place to start might be the methods for customizing tibble printing (since we are already using tibbles): https://pillar.r-lib.org/articles/extending.html

[paul-buerkner]

How relevant will this issue still be in light of implementing #257?