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Hello, I am working on a sage graph project, and for optimization, I have chosen to move it to cython. The code compiles just fine as is, but for further optimization I will need to use a union find data structure in my cdef function. So far, I was using DisjointSet from sage.sets.disjoint_set in a separate function : my issue is I do not know how to cdef such an object.

My initial attempt to solve this was to cimport the disjoint set class from the sage.sets.disjoint_set.pyx file, and use it to cdef.

This would in summary be something like this :

...
 
from sage.sets.disjoint_set cimport DisjointSet
 
cdef DisjointSet D
 
D = DisjointSet(10)
 
...

Though this does not compile : I get an error related to a library (that I assumed was included in the install of sage).
Just in case it was not, I manually installed GAP (which did not solve the problem).
 
/usr/bin/ld : ne peut trouver -lgap
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-g++' failed with exit status 1
 
(this message is in french but it translates exactly to "/usr/bin/ld: cannot find -lgap")
 
I believe this is mostly likely due to me misunderstanding how to import a class from the sage cython files. 
I had a similar problem when trying to work with bitsets (although the error was on the library pari instead of gap)
 
In case it is relevant, I am working on Ubuntu 20.04, installed sage with apt (sage version is 9.0).
 
Thank you in advance for any help.
 
Pierre
 

Hello, Hello,

I am working on a sage Sage graph project, and for optimization, optimization, I have chosen to move it to cython. Cython. The code compiles just fine as is, but for further optimization optimization I will need to use a union find data structure in my cdef function. cdef function. So far, I was using DisjointSet from sage.sets.disjoint_set DisjointSet from sage.sets.disjoint_set in a separate function : function: my issue is I do not know know how to cdef cdef such an object.

My initial attempt to solve this was to cimport cimport the disjoint set class from the sage.sets.disjoint_set.pyx file, sage/sets/disjoint_set.pyx file, and use it to cdef.cdef.

This would in summary be something like this :

...
 
...

from sage.sets.disjoint_set cimport DisjointSet
 
DisjointSet

cdef DisjointSet D
 
D

    D = DisjointSet(10)
 
DisjointSet(10)

...
 

Though this does not compile : I get an error related to a library library (that I assumed was included in the install of sage). Sage). Just in case it was not, I manually installed GAP GAP (which did not solve the problem).

/usr/bin/ld : ne peut trouver -lgap
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-g++' failed with exit status 1
 
(this 

/usr/bin/ld: cannot find -lgap")
-lgap

Hello,

I am working on a Sage graph project, and for optimization, I have chosen to move it to Cython. The code compiles just fine as is, but for further optimization I will need to use a union find data structure in my cdef function. So far, I was using DisjointSet from sage.sets.disjoint_set in a separate function: my issue is I do not know how to cdef such an object.

My initial attempt to solve this was to cimport the disjoint set class from the sage/sets/disjoint_set.pyx file, and use it to cdef.

This would in summary be something like this :

...

from sage.sets.disjoint_set cimport DisjointSet

cdef DisjointSet D

 D = DisjointSet(10)

...

Though this does not compile : I get an error related to a library (that I assumed was included in the install of Sage). Just in case it was not, I manually installed GAP (which did not solve the problem).

/usr/bin/ld : ne peut trouver -lgap
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-g++' failed with exit status 1

This message is partly in French but it translates exactly to

/usr/bin/ld: cannot find -lgap

I believe this is mostly likely due to me misunderstanding how to import a class from the Sage Cython files. I had a similar problem when trying to work with bitsets (although the error was on the library PARI instead of GAP).

In case it is relevant, I am working on Ubuntu 20.04, installed Sage with apt (Sage version is 9.0).

Thank you in advance for any help.

Pierre

Hello,

I am working on a Sage graph project, and for optimization, I have chosen to move it to Cython. The code compiles just fine as is, but for further optimization I will need to use a union find data structure in my cdef function. So far, I was using DisjointSet from sage.sets.disjoint_set in a separate function: my issue is I do not know how to cdef such an object.

My initial attempt to solve this was to cimport the disjoint set class from the sage/sets/disjoint_set.pyx file, and use it to cdef.

This would in summary be something like this :

...

from sage.sets.disjoint_set cimport DisjointSet
DisjointSet_of_hashables

cdef DisjointSet DisjointSet_of_hashables D

D = DisjointSet(10)

...

Though this does not compile : I get an error related to a library (that I assumed was included in the install of Sage). Just in case it was not, I manually installed GAP (which did not solve the problem).

/usr/bin/ld : ne peut trouver -lgap
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-g++' failed with exit status 1

This message is partly in French but it translates exactly to

/usr/bin/ld: cannot find -lgap

I believe this is mostly likely due to me misunderstanding how to import a class from the Sage Cython files. I had a similar problem when trying to work with bitsets (although the error was on the library PARI instead of GAP).

In case it is relevant, I am working on Ubuntu 20.04, installed Sage with apt (Sage version is 9.0).

Thank you in advance for any help.

Pierre