Surprising behavior of deletecolumn! and show

[leostenzel]

Hi & thanks for your package,

I was just trying out the example, and was a bit surprised that the final matrix shows

 [1, 1] = 2 
 [1, 2] = 3 
 [1, 3] = 4 
 [1, 4] = 1 

 [nothing, 1] = 3 
 [nothing, 6] = 5 
 [nothing, 8] = 7  

It appears that either deletecolumn! needs to delete the corresponding element of col_keys, or the tmp counter in show does not work correctly?

Slightly related: It was a bit confusing to me that show seems to exchange the order of indices. I.e., matrix[4,1] = 1 added an entry [1, 4] = 1…

Lastly an easy fix, there's an s too much after throw:

DynamicSparseArrays.jl/src/pcsr.jl

Line 207 in ef66de4

col_key != col && throws(ArgumentError("column $(col) does not exist."))

[guimarqu]

Hi thanks for the report,

Can you send me your example please?
I think the issue comes from show because it was implemented very quickly.

The order is indeed not correct.

[leostenzel]

Ah, sorry, I just c&p the example from the github page:

using DynamicSparseArrays
I = [1, 2, 3, 2, 6, 7, 1, 6, 8] #rows
J = [1, 1, 1, 2, 2, 2, 3, 3, 3] #columns
V = [2, 3, 4, 2, 4, 5, 3, 5, 7] #value
matrix = dynamicsparse(I,J,V) # create a matrix

matrix[4,1] = 1 # new column
matrix[2,2] = 0 # delete value
deletecolumn!(matrix, 2) # delete column with id 2
matrix[2,6] == 0 # true

[guimarqu]

Thanks for the report. That was a bug in show. I release a new version when the fix is merged into master. You can find a brief description of the project here: https://atoptima.github.io/Coluna.jl/stable/dynamic_sparse_arrays/

[leostenzel]

Cool, that was quick :)
Thanks, I'll have a look!