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Max Alekseyev's profile - activity

2021-05-12 23:32:02 +0200 commented question A certain polyhedron-related computation: any way to get it quicker?

See https://doc.sagemath.org/html/en/thematic_tutorials/profiling.html and https://doc.sagemath.org/html/en/reference/mi

2021-05-12 23:29:48 +0200 marked best answer solver parameter not available in Mixed Integer Linear Programming

I'm getting the following error, while trying to set up IntegralityFocus for Gurobi backend in Sage 9.2:

sage: from sage_numerical_backends_gurobi.gurobi_backend import GurobiBackend as mysolver                                                                                                                                                               
sage: milp = MixedIntegerLinearProgram(solver=mysolver)                                                                                                                                                                                                 
sage: milp.solver_parameter("IntegralityFocus", 1)                                                                                                                                                                                                      
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
sage_numerical_backends_gurobi/gurobi_backend.pyx in sage_numerical_backends_gurobi.gurobi_backend.GurobiBackend.solver_parameter()

KeyError: 'IntegralityFocus'

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
<ipython-input-3-65373ae60dc1> in <module>
----> 1 milp.solver_parameter("IntegralityFocus", Integer(1))

/usr/local/SageMath.92/local/lib/python3.8/site-packages/sage/numerical/mip.pyx in sage.numerical.mip.MixedIntegerLinearProgram.solver_parameter (build/cythonized/sage/numerical/mip.c:16597)()
   2470             return self._backend.solver_parameter(name)
   2471         else:
-> 2472             self._backend.solver_parameter(name, value)
   2473 
   2474     cpdef sum(self, L):

sage_numerical_backends_gurobi/gurobi_backend.pyx in sage_numerical_backends_gurobi.gurobi_backend.GurobiBackend.solver_parameter()

ValueError: This parameter is not available. Enabling it may not be so hard, though.

Ok, it says "Enabling it may not be so hard, though." but HOW?

2021-05-12 23:29:48 +0200 commented answer solver parameter not available in Mixed Integer Linear Programming

@Emmanuel Charpentier I submitted a ticket https://trac.sagemath.org/ticket/31782 but nobody seems to care.

2021-05-12 21:41:33 +0200 commented question A certain polyhedron-related computation: any way to get it quicker?

Did you profile your code? Which function / block is a bottleneck?

2021-05-12 19:57:05 +0200 commented answer Reduction of the coefficients of a polynomial in sage

You may find description of methods available in Sage at https://doc.sagemath.org/html/en/reference/modules/sage/modules

2021-05-11 19:18:27 +0200 commented answer Reduction of the coefficients of a polynomial in sage

LLL has polynomial time - see https://en.wikipedia.org/wiki/Lenstra%E2%80%93Lenstra%E2%80%93Lov%C3%A1sz_lattice_basis_re

2021-05-11 17:58:57 +0200 commented answer Reduction of the coefficients of a polynomial in sage

It looks like CVP implementation in Sage uses a different approach than SVP (which is based on LLL) and is more time con

2021-05-11 17:55:28 +0200 commented answer Reduction of the coefficients of a polynomial in sage

It looks like CVP implementation in Sage uses a different approach than SVP (which is based on LLL) and is more time con

2021-05-11 16:11:38 +0200 commented answer Reduction of the coefficients of a polynomial in sage

It looks OK to me.

2021-05-11 01:35:34 +0200 commented answer Reduction of the coefficients of a polynomial in sage

In this case you need to take $C \approx \frac{\sqrt{N}}{64(j-1)}$ and use closest_vector(t) instead of shortest_vector(

2021-05-11 01:35:04 +0200 commented answer Reduction of the coefficients of a polynomial in sage

In this case you need to take $C \approx \frac{\sqrt{N}}{64(j-1)}$ and use closest_vector(t) instead of shortest_vector(

2021-05-11 00:58:56 +0200 commented answer Reduction of the coefficients of a polynomial in sage

In this case you need to take $C \approx \frac{\sqrt{N}}{64(j-1)}$ and use closest_vector(t) instead of shortest_vector(

2021-05-10 01:45:34 +0200 commented question RSA encryption and decryption

Can you illustrate this discrepancy with an actual example?

2021-05-10 01:44:43 +0200 answered a question Reduction of the coefficients of a polynomial in sage

If we understand "smaller" by absolute value, then the problem can be posed as finding a short vector in the lattice gen

2021-05-06 16:14:10 +0200 commented answer Bivariate Coppersmith method

Is depends on the size of RSA modulus. Say, there is negligible chance with a 2048-bit, let along 4096-bit, modulus.

2021-05-06 16:11:09 +0200 commented question Groebner basis step by step

At least 3 polynomials can be removed so that the Grobner basis will still remain trivial.

2021-05-05 21:55:42 +0200 commented answer Bivariate Coppersmith method

No, as we see that (25*a+11)*(27*b+1) is reducible (product of 2 factors).

2021-05-05 19:58:24 +0200 commented answer Bivariate Coppersmith method

I do not follow this question since it's about two polynomials, while Coppersmith method applies to a single polynomial.

2021-05-05 19:26:25 +0200 commented answer Bivariate Coppersmith method

Yes, Coppersmith method is applicable to (65-8 * b) * (67-8 * a) -1763 = 0, but not to 64*a^2*b^2-840*a^2*b+2600*a^2-856

2021-05-05 19:26:05 +0200 commented answer Bivariate Coppersmith method

Yes, Coppersmith method is applicable to (65-8 * b) * (67-8 * a) -1763 = 0, but not to 64*a^2*b^2-840*a^2*b+2600*a^2-856

2021-05-04 16:41:47 +0200 answered a question Bivariate Coppersmith method

I'm not sure what is exactly your concern about the bivariate Coppersmith method -- if it's about the theory, you'd bett

2021-05-04 16:11:49 +0200 commented question RSA encryption and decryption

The code works fine for me. What is your concern?

2021-05-04 16:09:58 +0200 answered a question quotient ring in Sage

If under Z2 you understand $\mathbb Z/2\mathbb Z$ (or $\mathrm{GF}(2)$), then the even coefficients in the ideal generat

2021-05-03 20:11:50 +0200 answered a question How to find difference table of DES S box in sage math?

Try: S.difference_distribution_table().str()

2021-05-02 04:33:11 +0200 commented question Bivariate Coppersmith method

Some implementation is available at https://github.com/ubuntor/coppersmith-algorithm

2021-04-30 22:23:39 +0200 received badge  Nice Answer (source)
2021-04-28 05:51:19 +0200 edited answer How to define function

We can create a random function as a substitution table (over arbitrary Cartesian power d of a finite object K, also doi

2021-04-28 04:17:46 +0200 edited answer How to define function

We can create a random function as a substitution table (over arbitrary Cartesian power d of a finite object K, also doi

2021-04-28 04:15:53 +0200 edited answer How to define function

We can create a random function as a substitution table (over arbitrary Cartesian power d of a finite object K, also doi

2021-04-28 04:12:47 +0200 answered a question How to define function

We can a random function as a substitution table (over arbitrary Cartesian power d of a finite object K, also doing some

2021-04-28 00:31:04 +0200 edited answer AttributeError: '...FunctionFieldElement_rational' object has no attribute 'series'

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z'

2021-04-28 00:28:35 +0200 edited answer AttributeError: '...FunctionFieldElement_rational' object has no attribute 'series'

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z'

2021-04-28 00:28:07 +0200 edited answer AttributeError: '...FunctionFieldElement_rational' object has no attribute 'series'

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z'

2021-04-28 00:27:21 +0200 answered a question AttributeError: '...FunctionFieldElement_rational' object has no attribute 'series'

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z'

2021-04-28 00:03:31 +0200 commented question Eliptic Curves - How to check that substract points cross/exceeds the order of curve n?

There is no such thing as "negative y1" since the point coordinates are elements of the field $\mathbb F_p$, and as such

2021-04-28 00:03:11 +0200 commented question Eliptic Curves - How to check that substract points cross/exceeds the order of curve n?

There is no such thing as "negative y1" since the point coordinates are elements of $F_p$, and as such they do not have

2021-04-26 15:31:58 +0200 received badge  Nice Answer (source)
2021-04-25 18:30:58 +0200 commented answer factor symbolic expression

I'm not sure what problem you are talking about as your code runs without an issue at Sagecell: https://sagecell.sagemat

2021-04-25 17:33:02 +0200 answered a question factor symbolic expression

Adding parentheses does the job: EGe0 = (pp*A*qq).collect(p)

2021-04-25 17:27:49 +0200 answered a question how to get value without e?

We can control how many decimal digits to print with formatted floating point output - for example, here we get 50 decim

2021-04-24 16:34:57 +0200 commented answer Rounding up to the nearest integer that’s congruent to k mod N

The multiples of P, that is $\{O,P,2P,\dots,(n-1)P\}$ forms a cyclic group. Since $n$ is odd, you can also define half_m

2021-04-24 16:34:18 +0200 commented answer Rounding up to the nearest integer that’s congruent to k mod N

The multiples of P, that is $\{O,P,2P,\dots,(n-1)P\}$ forms a cyclic group. Since $n$ is odd, you can also define half_m

2021-04-24 16:33:36 +0200 commented answer Rounding up to the nearest integer that’s congruent to k mod N

${O,P,2P,\dots,(n-1)P}$ forms a cyclic group. Since $n$ is odd, you can also define half_mod_n = (n+1) /2, and it is an

2021-04-23 15:58:23 +0200 commented answer Rounding up to the nearest integer that’s congruent to k mod N

It's not possible unless you know what multiple of P a given point is, which in general amounts to computing the discret

2021-04-23 03:49:05 +0200 answered a question Rounding up to the nearest integer that’s congruent to k mod N

"Rounding" in this case means simply adding P_05 like P_9_half_rounded = P_9_half + P_05 print(P_9_half_rounded == P *

2021-04-22 20:55:10 +0200 received badge  Good Answer (source)
2021-04-22 17:58:25 +0200 commented question How to combine bin packing with graph theory?

This may be better suited for https://math.stackexchange.com/ as your question is not Sage specific.

2021-04-22 06:09:19 +0200 edited answer How to create lists of n-tuples efficiently?

Each half of x can be viewed as a subset of size q of the corresponding set: {0,1,...,pq-1} and {pq,pq+1,...,2pq-1}, res

2021-04-22 06:02:31 +0200 answered a question How to create lists of n-tuples efficiently?

Each half of x can be viewed as a subset of size q of the corresponding set: {0,1,...,pq-1} and {pq,pq+1,...,2pq-1}, res

2021-04-12 06:42:25 +0200 commented answer list of all prime powers -1

For example: for q in PP: if q>=100: break print(q)