Discussion related to cado-nfs

[Emmanuel Thomé <Emmanuel.Thome@inria.fr>]

Hi

mf_scan no longer exists.

How do you end up having to deal with ascii matrices? Cado-nfs doesn't produce them (although it's true that some binaries still have provision to do so, it's not normal behaviour, and I intend to get rid of those code paths). By and large, the matrix format, even in binary, is trivial enough that you can probably either produce it directly, or write a small conversion tool. For example for a factoring matrix (DLP is only mildly different as it includes signed 32-bit coefficients), here goes.

import sys
import struct
it = iter(sys.stdin)
header_line = next(it)   # remove this if you have no header line
data = "open("matrix.bin"," "wb")
for line in it:
    w, *cols = [int(x) for x in line.strip().split()]
    assert w == len(cols)
    data.write(struct.pack("<I", w))
    for j in cols:
        data.write(struct.pack("<I", j))

# to create the .rw.bin and .cw.bin files, do:    linalg/bwc/mf_scan2   matrix.bin

Since I don't intend to maintain a "cado-nfs text format" for matrices which I in fact would not use, I don't think that such a conversion tool should reside in the cado-nfs tree.

Best regards,

E.

On Thu, Dec 26, 2024 at 10:47 AM Jhon Alejandro M <alejandromelo@unicauca.edu.co> wrote:

In previous versions of cado I used mf_scan to convert a matrix from acci format to binary, but I can no longer find the mf_scan file to perform this transformation, how can I convert the matrix now?

thanks for any help