[julia-users] Re: Boolean operations on arrays?
It looks like I can get the right effect using component-wise
multiplication:
julia> ![true, true, false] .* [false, true, true]
3-element Array{Bool,1}:
false
false
true
Is this the correct solution or is this an ugly hack?
Cheers,
Daniel.
On 21 September 2015 at 14:35, Daniel Carrera wrote:
> Hello,
>
> I have two boolean arrays and I am trying to obtain the boolean array
> resulting from a component-wise `AND`:
>
> julia> [true, true, false] .&& [false, true, true]
> ERROR: syntax: invalid identifier name "&&"
>
> julia> [true, true, false] .& [false, true, true]
> ERROR: type Array has no field &
>
>
> Can anyone figure out what I'm doing wrong? I was hoping that `.&` and
> `.&&` would apply the operation on a per-component basis. Help?
>
> Cheers,
> Daniel.
>
[julia-users] Re: Boolean operations on arrays?
The bitwise operations (&, |) broadcast over arrays and work just fine for
this. Watch out for their precedence, though: you need to wrap them in
parentheses if you want to combine them with the result of comparisons `(A
== 1) | (A == 2)`.
On Monday, September 21, 2015 at 8:41:29 AM UTC-4, Daniel Carrera wrote:
>
> It looks like I can get the right effect using component-wise
> multiplication:
>
> julia> ![true, true, false] .* [false, true, true]
> 3-element Array{Bool,1}:
> false
> false
> true
>
>
> Is this the correct solution or is this an ugly hack?
>
> Cheers,
> Daniel.
>
>
>
> On 21 September 2015 at 14:35, Daniel Carrera > wrote:
>
>> Hello,
>>
>> I have two boolean arrays and I am trying to obtain the boolean array
>> resulting from a component-wise `AND`:
>>
>> julia> [true, true, false] .&& [false, true, true]
>> ERROR: syntax: invalid identifier name "&&"
>>
>> julia> [true, true, false] .& [false, true, true]
>> ERROR: type Array has no field &
>>
>>
>> Can anyone figure out what I'm doing wrong? I was hoping that `.&` and
>> `.&&` would apply the operation on a per-component basis. Help?
>>
>> Cheers,
>> Daniel.
>>
>
>
[julia-users] Re: Boolean operations on arrays?
Note that the broadcasting works for sparse matrices only on recent builds.
On Monday, September 21, 2015 at 6:28:46 AM UTC-7, Matt Bauman wrote:
>
> The bitwise operations (&, |) broadcast over arrays and work just fine for
> this. Watch out for their precedence, though: you need to wrap them in
> parentheses if you want to combine them with the result of comparisons `(A
> == 1) | (A == 2)`.
>
> On Monday, September 21, 2015 at 8:41:29 AM UTC-4, Daniel Carrera wrote:
>>
>> It looks like I can get the right effect using component-wise
>> multiplication:
>>
>> julia> ![true, true, false] .* [false, true, true]
>> 3-element Array{Bool,1}:
>> false
>> false
>> true
>>
>>
>> Is this the correct solution or is this an ugly hack?
>>
>> Cheers,
>> Daniel.
>>
>>
>>
>> On 21 September 2015 at 14:35, Daniel Carrera wrote:
>>
>>> Hello,
>>>
>>> I have two boolean arrays and I am trying to obtain the boolean array
>>> resulting from a component-wise `AND`:
>>>
>>> julia> [true, true, false] .&& [false, true, true]
>>> ERROR: syntax: invalid identifier name "&&"
>>>
>>> julia> [true, true, false] .& [false, true, true]
>>> ERROR: type Array has no field &
>>>
>>>
>>> Can anyone figure out what I'm doing wrong? I was hoping that `.&` and
>>> `.&&` would apply the operation on a per-component basis. Help?
>>>
>>> Cheers,
>>> Daniel.
>>>
>>
>>
