Re: [julia-users] fill! with copies
Thanks all, those look like neat solutions.
--
Carlos
On Fri, May 16, 2014 at 11:36 PM, Stefan Karpinski wrote:
> When you write fill!(arr, ChannVals()) you are asking to fill arr with
> the one value that is the result of evaluating ChannVals() once. Doing
> anything else would be bizarre. We could have a version of fill! that takes
> a thunk so you could write
>
> fill!(arr) do
> ChannVals()
> end
>
>
> That would have the desired effect as well, but it seems to me that using
> a comprehension is just as easy in that case.
>
>
> On Fri, May 16, 2014 at 4:21 PM, Ivar Nesje wrote:
>
>> @Jameson They are immutable, but they contain references to mutable
>> arrays, and all the immutable types will reference the same arrays. That
>> way you would not just need a copy but a deepcopy. That will probably be
>> too much overhead for fill!(), and will be problematic if someone decided
>> to fill! an array with some large structure.
>>
>> On the other hand, I think it would be reasonable for fill! to take a
>> shallow copy of mutable types. Not sure what others think on that subject
>> though.
>>
>> Ivar
>>
>> kl. 17:01:56 UTC+2 fredag 16. mai 2014 skrev Jameson følgende:
>>>
>>> Since they are immutable, fill! did exactly what you wanted
>>>
>>> On Friday, May 16, 2014, Tim Holy wrote:
>>>
Try
arr = [ChannVals() for i = 1:10]
On Friday, May 16, 2014 01:27:18 AM Carlos Becker wrote:
> Hello all,
>
> I wanted to create an array of an immutable type and initialize an
empty
> copy in each (with the default constructor).
> I am wondering which is the best way to do it, so far:
>
>immutable ChannVals
> taus::Vector{Float64}
> alphas::Vector{Float64}
>
> ChannVals() = new( Float64[], Float64[] )
>end
>
># create 10 new instances
>arr = ChannVals[ChannVals() for i=1:10]
>
>
> Now, a neat but incorrect way is to do
>
>arr = Array( ChannVals, 10 )
>fill!(allVals, ChannVals())
>
> because it will fill them with the same instance.
> Is there a neat way, such as a fillwithcopies!() ?
>
>
> Cheers.
>>>
>
Re: [julia-users] fill! with copies
When you write fill!(arr, ChannVals()) you are asking to fill arr with the
one value that is the result of evaluating ChannVals() once. Doing anything
else would be bizarre. We could have a version of fill! that takes a thunk
so you could write
fill!(arr) do
ChannVals()
end
That would have the desired effect as well, but it seems to me that using a
comprehension is just as easy in that case.
On Fri, May 16, 2014 at 4:21 PM, Ivar Nesje wrote:
> @Jameson They are immutable, but they contain references to mutable
> arrays, and all the immutable types will reference the same arrays. That
> way you would not just need a copy but a deepcopy. That will probably be
> too much overhead for fill!(), and will be problematic if someone decided
> to fill! an array with some large structure.
>
> On the other hand, I think it would be reasonable for fill! to take a
> shallow copy of mutable types. Not sure what others think on that subject
> though.
>
> Ivar
>
> kl. 17:01:56 UTC+2 fredag 16. mai 2014 skrev Jameson følgende:
>>
>> Since they are immutable, fill! did exactly what you wanted
>>
>> On Friday, May 16, 2014, Tim Holy wrote:
>>
>>> Try
>>>
>>> arr = [ChannVals() for i = 1:10]
>>>
>>> On Friday, May 16, 2014 01:27:18 AM Carlos Becker wrote:
>>> > Hello all,
>>> >
>>> > I wanted to create an array of an immutable type and initialize an
>>> empty
>>> > copy in each (with the default constructor).
>>> > I am wondering which is the best way to do it, so far:
>>> >
>>> >immutable ChannVals
>>> > taus::Vector{Float64}
>>> > alphas::Vector{Float64}
>>> >
>>> > ChannVals() = new( Float64[], Float64[] )
>>> >end
>>> >
>>> ># create 10 new instances
>>> >arr = ChannVals[ChannVals() for i=1:10]
>>> >
>>> >
>>> > Now, a neat but incorrect way is to do
>>> >
>>> >arr = Array( ChannVals, 10 )
>>> >fill!(allVals, ChannVals())
>>> >
>>> > because it will fill them with the same instance.
>>> > Is there a neat way, such as a fillwithcopies!() ?
>>> >
>>> >
>>> > Cheers.
>>>
>>
Re: [julia-users] fill! with copies
@Jameson They are immutable, but they contain references to mutable arrays,
and all the immutable types will reference the same arrays. That way you
would not just need a copy but a deepcopy. That will probably be too much
overhead for fill!(), and will be problematic if someone decided to fill!
an array with some large structure.
On the other hand, I think it would be reasonable for fill! to take a
shallow copy of mutable types. Not sure what others think on that subject
though.
Ivar
kl. 17:01:56 UTC+2 fredag 16. mai 2014 skrev Jameson følgende:
>
> Since they are immutable, fill! did exactly what you wanted
>
> On Friday, May 16, 2014, Tim Holy > wrote:
>
>> Try
>>
>> arr = [ChannVals() for i = 1:10]
>>
>> On Friday, May 16, 2014 01:27:18 AM Carlos Becker wrote:
>> > Hello all,
>> >
>> > I wanted to create an array of an immutable type and initialize an empty
>> > copy in each (with the default constructor).
>> > I am wondering which is the best way to do it, so far:
>> >
>> >immutable ChannVals
>> > taus::Vector{Float64}
>> > alphas::Vector{Float64}
>> >
>> > ChannVals() = new( Float64[], Float64[] )
>> >end
>> >
>> ># create 10 new instances
>> >arr = ChannVals[ChannVals() for i=1:10]
>> >
>> >
>> > Now, a neat but incorrect way is to do
>> >
>> >arr = Array( ChannVals, 10 )
>> >fill!(allVals, ChannVals())
>> >
>> > because it will fill them with the same instance.
>> > Is there a neat way, such as a fillwithcopies!() ?
>> >
>> >
>> > Cheers.
>>
>
Re: [julia-users] fill! with copies
Since they are immutable, fill! did exactly what you wanted
On Friday, May 16, 2014, Tim Holy wrote:
> Try
>
> arr = [ChannVals() for i = 1:10]
>
> On Friday, May 16, 2014 01:27:18 AM Carlos Becker wrote:
> > Hello all,
> >
> > I wanted to create an array of an immutable type and initialize an empty
> > copy in each (with the default constructor).
> > I am wondering which is the best way to do it, so far:
> >
> >immutable ChannVals
> > taus::Vector{Float64}
> > alphas::Vector{Float64}
> >
> > ChannVals() = new( Float64[], Float64[] )
> >end
> >
> ># create 10 new instances
> >arr = ChannVals[ChannVals() for i=1:10]
> >
> >
> > Now, a neat but incorrect way is to do
> >
> >arr = Array( ChannVals, 10 )
> >fill!(allVals, ChannVals())
> >
> > because it will fill them with the same instance.
> > Is there a neat way, such as a fillwithcopies!() ?
> >
> >
> > Cheers.
>
Re: [julia-users] fill! with copies
Try
arr = [ChannVals() for i = 1:10]
On Friday, May 16, 2014 01:27:18 AM Carlos Becker wrote:
> Hello all,
>
> I wanted to create an array of an immutable type and initialize an empty
> copy in each (with the default constructor).
> I am wondering which is the best way to do it, so far:
>
>immutable ChannVals
> taus::Vector{Float64}
> alphas::Vector{Float64}
>
> ChannVals() = new( Float64[], Float64[] )
>end
>
># create 10 new instances
>arr = ChannVals[ChannVals() for i=1:10]
>
>
> Now, a neat but incorrect way is to do
>
>arr = Array( ChannVals, 10 )
>fill!(allVals, ChannVals())
>
> because it will fill them with the same instance.
> Is there a neat way, such as a fillwithcopies!() ?
>
>
> Cheers.
Re: [julia-users] fill! with copies
* correction, 'allVals' is 'arr' in the last line of code.
--
Carlos
On Fri, May 16, 2014 at 10:27 AM, Carlos Becker wrote:
> Hello all,
>
> I wanted to create an array of an immutable type and initialize an empty
> copy in each (with the default constructor).
> I am wondering which is the best way to do it, so far:
>
>immutable ChannVals
> taus::Vector{Float64}
> alphas::Vector{Float64}
>
> ChannVals() = new( Float64[], Float64[] )
>end
>
># create 10 new instances
>arr = ChannVals[ChannVals() for i=1:10]
>
>
> Now, a neat but incorrect way is to do
>
>arr = Array( ChannVals, 10 )
>fill!(allVals, ChannVals())
>
> because it will fill them with the same instance.
> Is there a neat way, such as a fillwithcopies!() ?
>
>
> Cheers.
>
