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Diffstat (limited to '2.3-1/src/c/linearAlgebra/projspec/dprojspeca.c')
-rw-r--r-- | 2.3-1/src/c/linearAlgebra/projspec/dprojspeca.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/2.3-1/src/c/linearAlgebra/projspec/dprojspeca.c b/2.3-1/src/c/linearAlgebra/projspec/dprojspeca.c new file mode 100644 index 00000000..aea9713e --- /dev/null +++ b/2.3-1/src/c/linearAlgebra/projspec/dprojspeca.c @@ -0,0 +1,67 @@ +/* Copyright (C) 2017 - IIT Bombay - FOSSEE + + This file must be used under the terms of the CeCILL. + This source file is licensed as described in the file COPYING, which + you should have received as part of this distribution. The terms + are also available at + http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt + Author: Sandeep Gupta + Organization: FOSSEE, IIT Bombay + Email: toolbox@scilab.in + */ + +/* PROJSPEC function in scilab */ + +/* + //[S,P,D,index]=projspec(A) + //Spectral characteristics of A at 0 + //S = reduced resolvent at 0 (S=-Drazin_inverse(A)) + //P = spectral projection at 0 + //D = Nilpotent operator at 0 + //index = index of the 0 eigenvalue + //! + +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <math.h> +#include "norm.h" +#include "eye.h" + +#define eps pow(2,-52) + +double dprojspeca(double *inp1,int row,int col,double *out1,double *out2,double *out3){ + double tol = pow(10,-6); + int i,j,index; + /*norm(A,1)*/ + double nor; + nor = dnorma(inp1,row,col,1); + + /* P=eye(A),D=A,S=0*P;index=1; */ + if(nor < eps*row*row){ + memcpy(out2,inp1,row*col*sizeof(double)); + deyea(out2,row,col); + memcpy(out3,inp1,row*col*sizeof(double)); + for(i=0;i<row;i++){ + for(j=0;j<row;j++){ + out1[i*row+j] = 0; + } + } + index = 1; + } + + /* rcond(A) */ + double *rcon; + rcon = rcond(inp1,row); + if(rcon > tol){ + dinverma(inp1,out1,row); + for(i=0;i<row*col;i++){ + out2[i]=0; + out3[i]=0; + } + index = 0; + return index; + } + index = 1; +} |