[julia-users] Re: Help: Printing method in julia
OK, I see. Thank you! On Wednesday, September 21, 2016 at 6:17:30 PM UTC-5, Steven G. Johnson wrote: > > > > On Wednesday, September 21, 2016 at 4:24:10 PM UTC-4, Weicheng Zhu wrote: >> >> Hi Dr. Johnson, >> Thank you very much for your help! Not I understand how it works. >> This problem has confused me a long time since I started learning julia. >> >> So if I want a `mytype` object to be printed in the pretty-printed lines >> by default, I have to define the display method, right? >> > > No. Only override show, not display. And in Julia 0.4 the 3-argument > show is called writemime, not show. >
[julia-users] Re: Help: Printing method in julia
On Wednesday, September 21, 2016 at 4:24:10 PM UTC-4, Weicheng Zhu wrote: > > Hi Dr. Johnson, > Thank you very much for your help! Not I understand how it works. > This problem has confused me a long time since I started learning julia. > > So if I want a `mytype` object to be printed in the pretty-printed lines > by default, I have to define the display method, right? > No. Only override show, not display. And in Julia 0.4 the 3-argument show is called writemime, not show.
[julia-users] Re: Help: Printing method in julia
OK, I see.
It seems that if I define the two show method directly in the REPL, it
doesn't work. But it works when I wrap them into a module:)
On Wednesday, September 21, 2016 at 3:24:10 PM UTC-5, Weicheng Zhu wrote:
>
> Hi Dr. Johnson,
> Thank you very much for your help! Not I understand how it works.
> This problem has confused me a long time since I started learning julia.
>
> So if I want a `mytype` object to be printed in the pretty-printed lines
> by default, I have to define the display method, right?
> I guess my definition of the display method is not quite correct, although
> it works in REPL.
>
>
>> import Base.show
>> type mytype
>> x::Array{Float64,2}
>> end
>> function show(io::IO, x::mytype)
>> show(io, x.x)
>> end
>> function show(io::IO, m::MIME"text/plain", x::mytype)
>> show(io, m, x.x)
>> end
>> show(STDOUT, MIME("text/plain"), mytype(x))
>> function Base.display(x::mytype)
>> println("mytype object:")
>> show(STDOUT, MIME("text/plain"), x)
>> end
>> julia> x = rand(5,2)
>> julia> mytype(x)
>> mytype object:
>> 5×2 Array{Float64,2}:
>> 0.05127 0.908138
>> 0.527729 0.835109
>> 0.657212 0.275374
>> 0.119597 0.659259
>> 0.94996 0.36432
>
>
>
> On Wednesday, September 21, 2016 at 2:27:18 PM UTC-5, Steven G. Johnson
> wrote:
>>
>>
>>
>> On Wednesday, September 21, 2016 at 2:54:15 PM UTC-4, Weicheng Zhu wrote:
>>>
>>> Hi all,
>>>
>>> I have a few simple questions to ask.
>>>
>>> 1) What function is invoked when I type x in the following example?
>>>
>>
>> display(x), which calls show(STDOUT, MIME("text/plain"), x) [or
>> writemime in Julia ≤ 0.4]
>>
>>
>> (Under the hood, this eventually calls a function Base.showarray)
>>
>>
>> 2) When I define a type which takes a matrix as a member, how to define
>>> the show method to print x as shown above in julia 0.5.
>>> julia> type mytype
>>>x::Array{Float64,2}
>>> end
>>> julia> mytype(x)
>>> mytype([0.923288 0.0157897; 0.439387 0.50823; … ; 0.605268 0.416877;
>>> 0.223898 0.558542])
>>
>>
>> You want to define two show methods: show(io::IO, x::mytype), which calls
>> show(io, x.x) and outputs everything on a single line, and show(io::IO,
>> m::MIME"text/plain", x::mytype), which calls show(io, m, x.x) and outputs
>> multiple pretty-printed lines.
>>
>>
>> (You can also define additional show methods, e.g. for HTML or Markdown
>> output, for even nicer display in an environment like IJulia that supports
>> other MIME types.)
>>
>
[julia-users] Re: Help: Printing method in julia
Hi Dr. Johnson,
Thank you very much for your help! Not I understand how it works.
This problem has confused me a long time since I started learning julia.
So if I want a `mytype` object to be printed in the pretty-printed lines by
default, I have to define the display method, right?
I guess my definition of the display method is not quite correct, although
it works in REPL.
> import Base.show
> type mytype
> x::Array{Float64,2}
> end
> function show(io::IO, x::mytype)
> show(io, x.x)
> end
> function show(io::IO, m::MIME"text/plain", x::mytype)
> show(io, m, x.x)
> end
> show(STDOUT, MIME("text/plain"), mytype(x))
> function Base.display(x::mytype)
> println("mytype object:")
> show(STDOUT, MIME("text/plain"), x)
> end
> julia> x = rand(5,2)
> julia> mytype(x)
> mytype object:
> 5×2 Array{Float64,2}:
> 0.05127 0.908138
> 0.527729 0.835109
> 0.657212 0.275374
> 0.119597 0.659259
> 0.94996 0.36432
On Wednesday, September 21, 2016 at 2:27:18 PM UTC-5, Steven G. Johnson
wrote:
>
>
>
> On Wednesday, September 21, 2016 at 2:54:15 PM UTC-4, Weicheng Zhu wrote:
>>
>> Hi all,
>>
>> I have a few simple questions to ask.
>>
>> 1) What function is invoked when I type x in the following example?
>>
>
> display(x), which calls show(STDOUT, MIME("text/plain"), x) [or writemime
> in Julia ≤ 0.4]
>
>
> (Under the hood, this eventually calls a function Base.showarray)
>
>
> 2) When I define a type which takes a matrix as a member, how to define
>> the show method to print x as shown above in julia 0.5.
>> julia> type mytype
>>x::Array{Float64,2}
>> end
>> julia> mytype(x)
>> mytype([0.923288 0.0157897; 0.439387 0.50823; … ; 0.605268 0.416877;
>> 0.223898 0.558542])
>
>
> You want to define two show methods: show(io::IO, x::mytype), which calls
> show(io, x.x) and outputs everything on a single line, and show(io::IO,
> m::MIME"text/plain", x::mytype), which calls show(io, m, x.x) and outputs
> multiple pretty-printed lines.
>
>
> (You can also define additional show methods, e.g. for HTML or Markdown
> output, for even nicer display in an environment like IJulia that supports
> other MIME types.)
>
[julia-users] Re: Help: Printing method in julia
On Wednesday, September 21, 2016 at 2:54:15 PM UTC-4, Weicheng Zhu wrote:
>
> Hi all,
>
> I have a few simple questions to ask.
>
> 1) What function is invoked when I type x in the following example?
>
display(x), which calls show(STDOUT, MIME("text/plain"), x) [or writemime
in Julia ≤ 0.4]
(Under the hood, this eventually calls a function Base.showarray)
2) When I define a type which takes a matrix as a member, how to define the
> show method to print x as shown above in julia 0.5.
> julia> type mytype
>x::Array{Float64,2}
> end
> julia> mytype(x)
> mytype([0.923288 0.0157897; 0.439387 0.50823; … ; 0.605268 0.416877;
> 0.223898 0.558542])
You want to define two show methods: show(io::IO, x::mytype), which calls
show(io, x.x) and outputs everything on a single line, and show(io::IO,
m::MIME"text/plain", x::mytype), which calls show(io, m, x.x) and outputs
multiple pretty-printed lines.
(You can also define additional show methods, e.g. for HTML or Markdown
output, for even nicer display in an environment like IJulia that supports
other MIME types.)
