[Jprogramming] sparse scatter-modify

[Henry Rich]

Yes, the definition of m} changed for m of rank > 1, but the sparse code 
doesn't support that.  You will need to use

1 (<"1 I) } 1 $. 8 8 ; 0 1 ; 0

Henry Rich


On 12/1/2020 7:25 PM, Hauke Rehr wrote:
> Very interesting indeed.
>
> Output of
> 1 I } 8 8 $ 0
> differs from 8.07 to 9.01
> (8.07: all ones) but
> 1 I } 1 $. 8 8 ; 0 1 ; 0
> is the same.
>
> Am 02.12.20 um 01:16 schrieb David Lambert:
>> matrix representation of a graph failure
>> ( https://adventofcode.com/2019/day/6 )
>>
>>     JVERSION
>> Engine: j901/j64avx2/windows
>> Release-c: commercial/2020-01-11T13:29:14
>> Library: 9.01.22
>> Platform: Win 64
>> Installer: J901 install
>> InstallPath: c:/program files/j901
>> Contact: www.jsoftware.com
>>
>>     I=:_2]\0 1 2 3 4 5 6 7 1 0 3 2 5 4 7 6
>>
>>     1 I } 8 8 $ 0
>> 0 1 0 0 0 0 0 0
>> 1 0 0 0 0 0 0 0
>> 0 0 0 1 0 0 0 0
>> 0 0 1 0 0 0 0 0
>> 0 0 0 0 0 1 0 0
>> 0 0 0 0 1 0 0 0
>> 0 0 0 0 0 0 0 1
>> 0 0 0 0 0 0 1 0
>>
>>     1 I } 1 $. 8 8 ; 0 1 ; 0
>> 0 0 | 1
>> 0 1 | 1
>> 0 2 | 1
>> (snip)
>> 7 3 | 1
>> 7 4 | 1
>> 7 5 | 1
>> 7 6 | 1
>> 7 7 | 1
>>
>> Stay well!  Dave
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>


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