与cvx_begin的matlab cvx错误

Question

由于某种原因,cvx不能为我开箱即用.

我使用windows x64,cvx x64和Matlab x64 R2012a

但是,当我运行简单的例子(\ cvx\examples\quickstart.m)时,它给我一个错误:

>> quickstart

has_quadprog = exist( 'quadprog' );
has_quadprog = has_quadprog == 2 | has_quadprog == 3;
has_linprog  = exist( 'linprog' );
has_linprog  = has_linprog == 2 | has_linprog == 3;
rnstate = randn( 'state' ); randn( 'state', 1 );
s_quiet = cvx_quiet(true);
s_pause = cvx_pause(false);
cvx_clear; echo on

prob = evalin( 'caller', 'cvx_problem', '[]' );
if isa( prob, 'cvxprob' ),

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% SECTION 2.1: LEAST SQUARES %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Input data
m = 16; n = 8;
A = randn(m,n);
b = randn(m,1);

% Matlab version
x_ls = A \ b;

% cvx version
cvx_begin
Attempt to reference field of non-structure array.

Error in cvxprob (line 48)
    selected = cvx___.solvers.selected;

Error in cvx_begin (line 41)
assignin( 'caller', 'cvx_problem', cvxprob( varargin{:} ) );

Error in quickstart (line 25)
cvx_begin

Answer 1

安装相对简单:

1. 下载CVX(我得到的cvx-rd.zip发行版只包含免费解算器,所有支持的平台都包含预编译的MEX二进制文件).

2. 比如说解压缩ZIP文件 C:\cvx

3. 在MATLAB中导航到该目录,然后运行cvx_setup:

   >> cd('C:\cvx')
   >> cvx_setup
   
   ---------------------------------------------------------------------------
   CVX: Software for Disciplined Convex Programming       (c)2014 CVX Research
   Version 2.1, Build 1088 (e790d80)                  Sat Sep 20 22:03:02 2014
   ---------------------------------------------------------------------------
   Installation info:
       Path: C:\cvx
       MATLAB version: 8.3 (R2014a)
       OS: Windows 8 amd64 version 6.2
       Java version: 1.7.0_11
   Verfying CVX directory contents:
       No missing files.
   Preferences: none found; defaults loaded.
   ---------------------------------------------------------------------------
   Setting CVX paths...done.
   Saving updated path...done.
   Searching for solvers...3 shims found.
   2 solvers initialized (* = default):
    *  SDPT3    4.0     {cvx}\sdpt3
       SeDuMi   1.34    {cvx}\sedumi
   1 solver skipped:
       GLPK             
           Could not find a GLPK installation.
   Saving updated preferences...done.
   Testing with a simple model...done!
   ---------------------------------------------------------------------------
   To change the default solver, type "cvx_solver <solver_name>".
   To save this change for future sessions, type "cvx_save_prefs".
   Please consult the users' guide for more information.
   ---------------------------------------------------------------------------
   

4. 现在您可以运行以下示例之一:

   >> cd('C:\cvx\examples')
   >> quickstart
   

如果要连接外部解算器(Gurobi和MOSEK),请阅读文档中的相应部分.这需要CVX Professional许可证.