Displaying unitful dataframes

General Usage
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#1

What is the recommended procedure for displaying Unitful Dataframes?
Example:

using DataFrames, Unitful
d = (0:10:1000)u"m"
v = 1500u"m/s" .+ 1.5u"1/s"*d
t = [0u"s"; cumsum(diff(d) ./ v[1:end-1])]
df = DataFrame(depth=d, velocity=v, time=t)

df displays like this:

 Row │ depth      velocity       time
     │ Quantity…  Quantity…      Quantity…    
─────┼────────────────────────────────────────
   1 │       0 m  1500.0 m s^-1         0.0 s
   2 │      10 m  1515.0 m s^-1  0.00666667 s
   3 │      20 m  1530.0 m s^-1   0.0132673 s
  ⋮  │     ⋮            ⋮             ⋮
  99 │     980 m  2970.0 m s^-1    0.457052 s
 100 │     990 m  2985.0 m s^-1    0.460419 s
 101 │    1000 m  3000.0 m s^-1    0.463769 s

Ideally, the units should appear clearly and only below the column names. Thank you.

#2

I don’t know if someone has made this, but it definitely sounds like a good PR for PrettyTables, or a UnitfulDataFrames package, depending on the former’s policy on dependencies (Add it to the list of packages that would be obsoleted with Proposal for first class support of conditional dependencies in Pkg · Issue #1285 · JuliaLang/Pkg.jl · GitHub)

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#3

Thank you for the feedback.

It seems that PrettyTables.jl can already be used as is but one needs to labor a bit and precondition the inputs as follows:

using DataFrames, Unitful, PrettyTables

d = (0:10:1000)u"m"
v = 1500u"m/s" .+ 1.5u"1/s"*d
t = [0u"s"; cumsum(diff(d) ./ v[1:end-1])]
df = DataFrame(depth=d, velocity=v, time=t)
sunits = [unit(d[1]), unit(v[1]), unit(t[1])]
header = permutedims([names(df) sunits])
pretty_table(ustrip.(df), header; formatters = ft_printf("%.4f",[3]))

Result:

┌───────┬──────────┬────────┐
│ depth │ velocity │   time │
│     m │   m s^-1 │      s │
├───────┼──────────┼────────┤
│     0 │   1500.0 │ 0.0000 │
│    10 │   1515.0 │ 0.0067 │
│    20 │   1530.0 │ 0.0133 │
│    30 │   1545.0 │ 0.0198 │
│    40 │   1560.0 │ 0.0263 │
│    50 │   1575.0 │ 0.0327 │
│    60 │   1590.0 │ 0.0390 │
│   ⋮   │    ⋮     │   ⋮    │
└───────┴──────────┴────────┘
              94 rows omitted

NB: use keyword argument crop=:none to show all

Copying @Ronis_BR to ask if this could be automated.

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#4

Single-argument ustrip is a bit dangerous. If this is automated, it should probably use ustrip.(units, quantities)

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