How to get a function to print stuff with REPL-like formatting

New to Julia
1

Sometimes it’s easier if what gets printed by a function looks nice (like in the REPL):

function printout(x)
    println("x is: ",x)
end

Ex 1. Beautiful formatting that can be instantly read and understood:

check = rand(2,10)
2×10 Array{Float64,2}:
 0.20608   0.675941  0.267637  0.231587  0.404712  0.628064  0.727315  0.292798  0.579271  0.00830696
 0.570077  0.440174  0.997781  0.842532  0.752924  0.360579  0.368976  0.264956  0.20852   0.166019

Ex. 2. Printing from inside a function: the first semi-colon is somewhere in there…

printout(check)
x is: [0.20607999980294323 0.6759405043446565 0.2676368465413639 0.23158728513903615 0.40471156297506106 
0.6280638109428014 0.7273151713873742 0.2927977847045118 0.5792709021856115 0.008306955592047194; 0.5700766059127313 0.4401739651076826 
0.9977809895843064 0.8425324418892446 0.7529240018391419 0.360578553537942 0.3689764314494348 0.26495555789141423 0.20851971242325895 0.1660188215790821]

How can I make printout() give me output like Ex. 1?

2 
printout(x) = show(stdout, MIME"text/plain"(), x)
4 Likes
3

Thanks @sostock, sorry that my post was unclear. I meant to ask how to print an intermediate value (not the returned value) from inside a function.

4

This works:

function printout(x)
    display(x)
end

check = rand(2,10);

printout(check);

2×10 Array{Float64,2}:
 0.571579  0.793269  0.68453  0.732311  0.316721  0.167078  0.521398  0.830209  0.546623  0.852014
 0.98618   0.240232  0.50574  0.282009  0.329084  0.804751  0.044719  0.320697  0.735516  0.254228
5

Not in general. display may not output to stdout, and may not output plain text. It may open a window and display an image, for example, or use HTML display in an IJulia window. If you explicitly want text/plain output, you should use show(stdout, "text/plain", x),

2 Likes
6

Thanks @stevengj, MWE for reference below:

function printout(x)
    show(stdout, "text/plain", x)
end

check = rand(2,10);

printout(check);

Array{Float64,2}:
0.833317  0.0797113  0.305283  0.848721  0.897141  0.99114   0.694138  0.28158    0.82193   0.520097
0.187817  0.439049   0.922296  0.141583  0.172123  0.244657  0.720784  0.0473979  0.610638  0.941219