ValueError: Rank(A) < p or Rank([P; A; G]) < n

[應雨軒]

Hi, I am learning how to use cvxopt to solve qp problems.
But I encountered some problems when I practicing some examples from this website
https://cvxopt.org/examples/tutorial/qp.html

My cvxopt version is 1.19,and I use python2.7

After I run this code, I got error message : ValueError: Rank(A) < p or Rank([P; A; G]) < n

Can some one give me some advices? Thank you

[Martin]

You most likely have redundant constraints. The rank condition is an assumption that is used in the KKT solver; see Quadratic Cone Programs in the user's guide. 

[應雨軒]

My code is below:

from cvxopt import matrix, solvers

Q = 2*matrix([ [2, .5], [.5, 1] ])
p = matrix([1.0, 1.0])

G = matrix([[-1.0,0.0],[0.0,-1.0]])

h = matrix([0.0,0.0])

A = matrix([1.0, 1.0], (1,2))

b = matrix(1.0)

sol=solvers.qp(Q, p, G, h, A, b)

I think there are not any redundant constraints, or there are something I didn't notice?

I can't successfully use cvxopt in pycharm, so I wonder if there are something wrong with my code, or maybe There are some problems when I install cvxopt

Thank you

Martin 在 2021年2月16日 星期二上午7:22:23 [UTC+8] 的信中寫道：

[Martin]

It appears to be a problem with your installation. The code that you posted produces the following output:

     pcost       dcost       gap    pres   dres

 0:  1.8889e+00  7.7778e-01  1e+00  2e-16  2e+00

 1:  1.8769e+00  1.8320e+00  4e-02  2e-16  6e-02

 2:  1.8750e+00  1.8739e+00  1e-03  2e-16  5e-04

 3:  1.8750e+00  1.8750e+00  1e-05  1e-16  5e-06

 4:  1.8750e+00  1.8750e+00  1e-07  1e-16  5e-08

Optimal solution found.

How did you install CVXOPT?

[應雨軒]

I use python 2.7,so I downloaded numpy cp27 and cvxopt cp27(red circle in the below pictures)

Then pip instal in pycharm

Are there anything wrong ?

Thank you

 

Martin <martin.skovg...@gmail.com> 於 2021年2月16日 週二 下午8:14寫道：

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[Martin]

This is an old version of CVXOPT and not an official release. Have you tried installing CVXOPT using "pip install cvxopt"? 

[應雨軒]

After I typed "pip install cvxopt "in my pycharm terminal,I got this error message 

I can't install cvxopt by using "pip install cvxopt

Martin <martin.skovg...@gmail.com> 於 2021年2月18日 週四 上午6:33寫道：

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