Linear dependence: Difference between revisions

Cmloegcmluin (talk | contribs)
Cmloegcmluin (talk | contribs)
Why row-rank always equals column-rank: eliminate unnecessary use of antitranspose; make same point more simply with a single transpose
Line 121: Line 121:


  <nowiki>
  <nowiki>
reverseEachRow[a_] := Reverse[a, 2];
reverseEachCol[a_] := Reverse[a];
antitranspose[a_] := reverseEachRow[reverseEachCol[a]];
P = {
P = {
   {1,  4/3,  4/3},
   {   1,  4/3,  4/3 },
   {0, -4/3, -1/3},
   {   0, -4/3, -1/3 },
   {0,  4/3,  1/3}
   {   0,  4/3,  1/3 }
};
};
Last[HermiteDecomposition[P]]
Last[HermiteDecomposition[P]]
antitranspose[Last[HermiteDecomposition[antitranspose[P]]]]  
Last[HermiteDecomposition[Transpose[P]]


→ {
→ {
     { 1,   0,   1},
     {   1,   0,   1 },
     { 0, 4/3, 1/3},
     {   0, 4/3, 1/3 },
     { 0,   0,   0}
     {   0,   0,   0 }
   }  
   }  
→ {
→ {
     { 0,   0,   0},
     { 1/3, 2/3, -2/3 },
     {-1,  4,  0},
     {   0,    1,  -1 },
     { 0, 4/3, 1/3}
     {   0,   0,   0 }
   } </nowiki>
   } </nowiki>


On the other hand, we have the [[minimax-E-copfr-S]] (or primes miniRMS-U) tuning of 12-ET, where <math>d</math> still equals <math>3</math> but now <math>r = 1</math>:
On the other hand, we have the [[minimax-E-copfr-S]] (or primes miniRMS-U) tuning of 12-ET, where <math>d</math> still equals <math>3</math> but now <math>r = 1</math>:


  <nowiki>M = {{12, 19, 28}};
  <nowiki>M = {{ 12, 19, 28 }};
G = PseudoInverse[M]
G = PseudoInverse[M]
→ {{12, 19, 28}} / 1289
→ {{ 12, 19, 28 }} / 1289


P = G.M
P = G.M
→ {
→ {
     { 12² , 12·19, 12·28},
     { 12² , 12·19, 12·28 },
     {19·12,  19² , 19·28},
     { 19·12,  19² , 19·28 },
     {28·12, 28·19,  28² }
     { 28·12, 28·19,  28² }
   } / 1289
   } / 1289


Line 160: Line 156:
antitranspose[Last[HermiteDecomposition[antitranspose[P]]]]  
antitranspose[Last[HermiteDecomposition[antitranspose[P]]]]  
→ {
→ {
     {12, 19, 28},
     { 12, 19, 28 },
     { 0,  0,  0},
     { 0,  0,  0 },
     { 0,  0,  0}
     { 0,  0,  0 }
   }/1289
   }/1289
→ {
→ {
     { 0, 0, 0},
     { 12, 19, 28 },
     { 0,  0,  0},
     { 0,  0,  0 },
     {12, 19, 28}
     { 0, 0, 0 }
   }/1289 </nowiki>
   }/1289 </nowiki>