time   calls  line
                  1 function [return1,return2] = spparms(arg1,arg2)
                  2 %SPPARMS Set parameters for sparse matrix routines.
                  3 %   SPPARMS('key',value) sets one or more of the "tunable" parameters 
                  4 %   used in the sparse routines, particularly sparse / and \.
                  5 %
                  6 %   SPPARMS, by itself, prints a description of the current settings.
                  7 %
                  8 %   If no input argument is present, values = SPPARMS returns a
                  9 %   vector whose components give the current settings.
                 10 %   [keys,values] = SPPARMS returns that vector, and also returns
                 11 %   a character matrix whose rows are the keywords for the parameters.
                 12 %
                 13 %   SPPARMS(values), with no output argument, sets all the parameters
                 14 %   to the values specified by the argument vector.
                 15 %
                 16 %   value = SPPARMS('key') returns the current setting of one parameter.
                 17 %
                 18 %   SPPARMS('default') sets all the parameters to their default settings.
                 19 %   SPPARMS('tight') sets the minimum degree ordering parameters to their 
                 20 %   "tight" settings, which may lead to orderings with less fill-in, but 
                 21 %   which makes the ordering functions themselves use more execution time.
                 22 %
                 23 %   The parameters with the default and "tight" values are:
                 24 %
                 25 %                    keyword       default       tight
                 26 %
                 27 %      values(1)     'spumoni'      0
                 28 %      values(2)     'thr_rel'      1.1          1.0
                 29 %      values(3)     'thr_abs'      1.0          0.0
                 30 %      values(4)     'exact_d'      0            1
                 31 %      values(5)     'supernd'      3            1
                 32 %      values(6)     'rreduce'      3            1
                 33 %      values(7)     'wh_frac'      0.5          0.5
                 34 %      values(8)     'autommd'      1            
                 35 %      values(9)     'autoamd'      1
                 36 %      values(10)    'piv_tol'      0.1
                 37 %      values(11)    'bandden'      0.5
                 38 %      values(12)    'umfpack'      1
                 39 %      values(13)    'sym_tol'      0.001
                 40 %      values(14)    'ldl_tol'      0.01
                 41 %
                 42 %   The meanings of the parameters are
                 43 %
                 44 %      spumoni:  The Sparse Monitor Flag controls diagnostic output;
                 45 %                0 means none, 1 means some, 2 means too much.
                 46 %      thr_rel,
                 47 %      thr_abs:  Minimum degree threshold is thr_rel*mindegree + thr_abs.
                 48 %      exact_d:  Nonzero to use exact degrees in minimum degree,
                 49 %                Zero to use approximate degrees.
                 50 %      supernd:  If > 0, MMD amalgamates supernodes every supernd stages.
                 51 %      rreduce:  If > 0, MMD does row reduction every rreduce stages.
                 52 %      wh_frac:  Rows with density > wh_frac are ignored in COLMMD.
                 53 %      autommd:  Nonzero to use SYMMMD and COLMMD orderings with \ and /.
                 54 %      autoamd:  Nonzero to use AMD or COLAMD ordering with CHOLMOD, UMFPACK,
                 55 %                and SuiteSparseQR in \ and /.
                 56 %      piv_tol:  Pivot tolerance used by LU-based (UMFPACK) \ and /.
                 57 %      bandden:  Backslash uses band solver if band density is > bandden.
                 58 %                If bandden = 1.0, never use band solver.
                 59 %                If bandden = 0.0, always use band solver.
                 60 %      umfpack:  Nonzero to use UMFPACK instead of the v4 LU-based solver
                 61 %                in \ and /.
                 62 %      sym_tol:  Symmetric pivot tolerance used by UMFPACK.  See LU for
                 63 %                more information about the role of the symmetric pivot
                 64 %                tolerance.
                 65 %      ldl_tol:  Pivot tolerance used by LDL-based (MA57) \ and /.
                 66 %
                 67 %   Note:
                 68 %   Solving symmetric positive definite matrices within \ and /:
                 69 %      The CHOLMOD CHOL-based solver uses AMD.
                 70 %   Solving general square matrices within \ and /:
                 71 %      The UMFPACK LU-based solver uses either AMD or a modified COLAMD.
                 72 %      The v4 LU-based solver uses COLMMD.
                 73 %   Solving rectangular matrices within \ and /:
                 74 %      The SuiteSparseQR QR-based solver uses COLAMD.
                 75 %   All of these algorithms respond to SPPARMS('autoamd') except for the
                 76 %   v4 LU-based, which responds to SPPARMS('autommd').
                 77 %
                 78 %   See also AMD, COLAMD, SYMAMD.
                 79 
                 80 %   Copyright 1984-2009 The MathWorks, Inc.
                 81 %   $Revision: 5.14.4.17 $  $Date: 2010/08/23 23:12:46 $
                 82 
                 83 % The following are "constants".
                 84 
            35   85 allkeys = ['spumoni' 
                 86            'thr_rel'
                 87            'thr_abs'
                 88            'exact_d'
                 89            'supernd'
                 90            'rreduce'
                 91            'wh_frac'
                 92            'autommd'
                 93            'autoamd'
                 94            'piv_tol'
                 95            'bandden'
                 96            'umfpack'
                 97            'sym_tol'
                 98            'ldl_tol'
                 99            'cholmod'
                100            'usema57'
                101            'usespqr'
                102            'chmodsp'];
            35  103 nparms = size(allkeys,1); 
            35  104 spuparmrange = 1:1;   % Which parameters pertain to SPUMONI? 
            35  105 mmdparmrange = 2:7;   % Which parameters pertain to minimum degree? 
            35  106 bslparmrange = 8:17;  % Which parameters pertain to sparse backslash? 
            35  107 cspparmrange = 18:18; 
            35  108 defaultparms = [0 1.1 1.0 0 3 3 0.5 1 1 0.1 0.5 1 0.001 0.01 1 1 1 0]'; 
            35  109 tightmmdparms   = [1.0 0.0 1 1 1 0.5]'; 
                110 
                111 % First find out what the current parameters are.
                112 
            35  113 oldvalues = zeros(nparms,1); 
            35  114 oldvalues(spuparmrange) = sparsfun('spumoni'); 
            35  115 oldvalues(mmdparmrange) = sparsfun('mmdset'); 
            35  116 oldvalues(bslparmrange) = sparsfun('slashset'); 
            35  117 oldvalues(cspparmrange) = sparsfun('chmodsp'); 
                118 
                119 % No input args, no output args:  Describe current settings.
            35  120 if nargin == 0 && nargout == 0 
                121     a = num2str(oldvalues(1));
                122     if oldvalues(1) 
                123       fprintf('SParse MONItor output level %s.\n', a);
                124     else 
                125       fprintf('No SParse MONItor output.\n');
                126     end
                127     a = num2str(oldvalues(2));
                128     b = num2str(oldvalues(3));
                129     fprintf('mmd: threshold = %s * mindegree + %s,\n', a, b);
                130     if oldvalues(4) 
                131         fprintf('     using exact degrees in A''*A,\n');
                132     else 
                133         fprintf('     using approximate degrees in A''*A,\n');
                134     end
                135     s = int2str(oldvalues(5));
                136     if oldvalues(5)
                137         fprintf('     supernode amalgamation every %s stages,\n', s);
                138     else
                139         fprintf('     no supernode amalgamation,');
                140     end
                141     s = int2str(oldvalues(6));
                142     if oldvalues(6) 
                143         fprintf('     row reduction every %s stages,\n', s);
                144     else
                145         fprintf('     no row reduction,\n');
                146     end
                147     a = num2str(100*oldvalues(7));
                148     if oldvalues(7)
                149         fprintf('     withhold rows at least %s%% dense in colmmd.\n', a);
                150     else
                151         fprintf('     no row withholding in colmmd.\n');
                152     end
                153     if oldvalues(8)
                154       fprintf('Minimum degree orderings used with v4 chol, lu, and qr in \\ and /.\n');
                155     else
                156       fprintf('No automatic orderings used with v4 chol, lu, and qr in \\ and /.\n');
                157     end
                158     if oldvalues(9)
                159       fprintf('Approximate minimum degree orderings used with CHOLMOD and UMFPACK in \\ and /.\n');
                160     else
                161       fprintf('No automatic orderings used with CHOLMOD and UMFPACK in \\ and /.\n');
                162     end
                163     a = num2str(oldvalues(10));
                164     fprintf('Pivot tolerance of %s used by UMFPACK in \\ and /.\n', a);
                165     a = num2str(oldvalues(11));
                166     fprintf('Backslash uses band solver if band density is > %s\n', a);
                167     if oldvalues(12)
                168         fprintf('UMFPACK used for lu in \\ and /.\n');
                169     else
                170         fprintf('v4 algorithm used for lu in \\ and /.\n');
                171     end
                172     a = num2str(oldvalues(13));
                173     fprintf('Symmetric pivot tolerance of %s used by UMFPACK in \\ and /.\n', a);
                174     a = num2str(oldvalues(14));
                175     fprintf('Pivot tolerance of %s used by MA57 in \\ and /.\n', a);
                176     return;
                177 
                178 % No input args, one or two output args:  Return current settings.
            35  179 elseif nargin == 0 && nargout > 0 
                180     if nargout <= 1
                181         return1 = oldvalues;
                182     else
                183         return1 = allkeys;
                184         return2 = oldvalues;
                185     end
                186     return;
                187 
                188 % One input arg of suitable size:  Reset all parameters.
  0.01      35  189 elseif nargin == 1 && length(arg1) == nparms && min(size(arg1)) == 1 
            14  190     if nargout > 0  
                191         error (message('MATLAB:spparms:TooManyOutputs'))
                192     end
            14  193     sparsfun('spumoni',arg1(spuparmrange)); 
            14  194     sparsfun('mmdset',arg1(mmdparmrange)); 
            14  195     sparsfun('slashset',arg1(bslparmrange)); 
            14  196     sparsfun('chmodsp',arg1(cspparmrange)); 
            14  197     return; 
                198 
                199 % Input arg 'tight':  Reset minimum degree parameters.
            21  200 elseif nargin == 1 && strcmpi(arg1,'tight') 
                201     if nargout > 0
                202         error (message('MATLAB:spparms:TooManyOutputs'))
                203     end
                204     newvalues = oldvalues;
                205     newvalues(mmdparmrange) = tightmmdparms;
                206     spparms(newvalues);
                207     return;
                208 
                209 % Input arg 'default':  Reset all parameters.
            21  210 elseif nargin == 1 && strcmpi(arg1,'default') 
                211     if nargout > 0
                212         error (message('MATLAB:spparms:TooManyOutputs'))
                213     end
                214     spparms(defaultparms);
                215     return;
                216 
                217 % One input arg:  Return one current setting.
            21  218 elseif (nargin == 1) 
             7  219     if ~ischar(arg1) 
                220         error (message('MATLAB:spparms:OptionNotString'))
                221     end
             7  222     if nargout > 1 
                223         error (message('MATLAB:spparms:TooManyOutputs'))
                224     end
             7  225     if size(arg1,1) > 1 
                226         error (message('MATLAB:spparms:TooManyParamsPerKeyword'))
                227     end
             7  228     key = lower(arg1); 
             7  229     for i = 1:nparms 
            56  230         if strcmp (key, allkeys(i,:)) 
             7  231             return1 = oldvalues(i); 
             7  232             return; 
                233         end
            49  234     end 
                235     error ('MATLAB:spparms:UnknownKeyword', ...
                236         'Unknown keyword parameter "%s".', key);
                237 
                238 % Two input args:  Reset some parameters.
            14  239 elseif (nargin == 2) 
            14  240     if ~ischar(arg1) 
                241         error (message('MATLAB:spparms:OptionNotString'));
                242     end
            14  243     if nargout > 0 
                244         error (message('MATLAB:spparms:TooManyOutputs'));
                245     end
            14  246     if size(arg1,1) ~= length(arg2) 
                247         error (message('MATLAB:spparms:ParamsMismatchKeywords'));
                248     end
            14  249     newvalues = oldvalues; 
            14  250     for k = 1:size(arg1,1) 
            14  251         key = lower(arg1(k,:)); 
            14  252         value = arg2(k); 
            14  253         found = 0; 
            14  254         for i = 1:nparms 
           112  255             if strcmp (key, allkeys(i,:)) 
            14  256                 newvalues(i) = value; 
            14  257                 found = 1; 
            14  258                 break 
                259             end
            98  260         end 
            14  261         if ~found 
                262             warning('MATLAB:spparms:UnknownKeyword', ...
                263                     'Unknown keyword parameter "%s" in SPPARMS.', key);
                264         end
            14  265     end 
            14  266     spparms(newvalues); 
            14  267     return; 
                268    
                269 % No error is possible here.
                270 else
                271     error (message('MATLAB:spparms:InvalidArgs'))
                272 end