{VERSION 3 0 "IBM RISC UNIX" "3.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 } {CSTYLE "2D Output" 2 20 "" 0 1 0 0 255 1 0 0 0 0 0 0 0 0 0 }{CSTYLE " " -1 256 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 257 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Maple Output" 0 11 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 3 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT 257 39 "The Singular Value Decomp osition (SVD):" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 60 "For any rectangular matrix A, with real or complex entrie s, " }}{PARA 0 "" 0 "" {TEXT -1 40 "there is a rectangular diagonal ma trix " }{XPPEDIT 18 0 "Sigma;" "6#%&SigmaG" }{TEXT -1 40 " containing only nonnegative real values" }}{PARA 0 "" 0 "" {TEXT -1 12 "(called \+ the " }{TEXT 256 15 "singular values" }{TEXT -1 55 " of A), and square unitary matrices U and V\n(for which " }{XPPEDIT 18 0 "V^H;" "6#)%\"V G%\"HG" }{TEXT -1 8 " is the " }{TEXT 258 20 "Hermitian transpose," } {TEXT -1 37 " i.e., the conjugated transpose of V)" }}{PARA 0 "" 0 "" {TEXT -1 43 "so that A can be decomposed as the product:" }}{PARA 0 " " 0 "" {TEXT -1 9 " " }{XPPEDIT 18 0 "A = U*Sigma*V^H;" "6#/% \"AG*(%\"UG\"\"\"%&SigmaGF')%\"VG%\"HGF'" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 4 "?Svd" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "?ht ranspose" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "with(linalg):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 7 "n := 3;" }}{PARA 11 "" 1 " " {XPPMATH 20 "6#>%\"nG\"\"$" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 21 "A := randmatrix(n,n);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%\"AG- %'matrixG6#7%7%\"#x\"#m\"#a7%!\"&\"#**!#h7%!#]!#7!#=" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 8 "rank(A);" }}{PARA 11 "" 1 "" {XPPMATH 20 " 6#\"\"$" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 90 "Singular_values \+ := evalf(Svd(A));\n# Maple insists this has to be done with \"evalf\" \+ outside" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%0Singular_valuesG-%'vecto rG6#7%$\"+/#=$>8!\"($\"+*zBL4\"F+$\"+4M#z)=!\")" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 23 "The singular values of " }{XPPEDIT 18 0 "A;" "6#%\"A G" }{TEXT -1 37 " are essentially the eigenvalues of " }{XPPEDIT 18 0 "A*A^T;" "6#*&%\"AG\"\"\")F$%\"TGF%" }{TEXT -1 1 " " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "map( x->sqrt(Re(evalf(x))),\n al lvalues([eigenvals( evalm( A &* transpose(A) ) )])\n);" }}{PARA 11 " " 1 "" {XPPMATH 20 "6#7%$\"+/#=$>8!\"($\"+/M#z)=!\")$\"+*zBL4\"F&" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 59 "We can also get the U and V matric es of the SVD as follows:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "Singular_values := evalf(Svd(A,U,V));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%0Singular_valuesG-%'vectorG6#7%$\"+/#=$>8!\"($\"+*zBL 4\"F+$\"+4M#z)=!\")" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 60 "Turn the s equence of singular values into a diagonal matrix." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "Sigma := diag( seq(Singular_values[i_],i_=1 ..n) );\n" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%&SigmaG-%'matrixG6#7%7% $\"+/#=$>8!\"(\"\"!F-7%F-$\"+*zBL4\"F,F-7%F-F-$\"+4M#z)=!\")" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 41 "evalm( A - U &* Sigma &* htr anspose(V) );" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%$\"\" \"!\")$\"\"$F*$!\"#F*7%$\"\"'!\"*F-$\"\"#F*7%\"\"!$!\"\"F*F6" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 13 "U is unitary." }}}{EXCHG {PARA 0 " > " 0 "" {MPLTEXT 1 0 9 "evalm(U);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6# -%'matrixG6#7%7%$!+t9(*Rx!#5$\"+#zNFw%F*$\"+p?VsTF*7%$!+[5//cF*$!+;P0? #)F*$!+E0k75F*7%$\"+XwYZHF*$!+P*G?7$F*$\"+:[NJ!*F*" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 7 "det(U);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$ \"+++++5!\"*" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "evalm(U &* \+ htranspose(U));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%$\" +**********!#5$!\"&!#6$\"\"\"F*7%F+$\"+++++5!\"*$\"#5F-7%F.F4F(" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 18 "V is unitary also." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "evalm(V);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%$!+5Y(>U&!#5$\"+7I'z:&F*$!+T$pIj'F*7%$! +l&y_M)F*$!+9uYDUF*$\"++:yNNF*7%$!+g\")Q!z*!#6$\"+\"*Gd_uF*$\"+?:]&f'F *" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 7 "det(V);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$\"+++++5!\"*" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "evalm(V &* htranspose(V));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%$\"+)*********!#5\"\"!F+7%F+$\"+++++5! \"*F+7%F+F+F-" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 73 "We can validate \+ that the Singular Value Decomposition really holds for A:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 39 "evalm(A - U &* Sigma &* htranspose( V));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%$\"\"\"!\")$\" \"$F*$!\"#F*7%$\"\"'!\"*F-$\"\"#F*7%\"\"!$!\"\"F*F6" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 41 "evalm( Sigma - htranspose(U) &* A &* V ); " }}{PARA 11 "" 1 "" {XPPMATH 20 "6#-%'matrixG6#7%7%\"\"!$!# " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "1 0 0" 1 }{VIEWOPTS 1 1 0 1 1 1803 }