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/*
ARPACK++ v1.2 2/20/2000
c++ interface to ARPACK code.
MODULE BNMatrxW.h
Class template for the n by n matrix A with entries
A(i,j) = k*(s(i))*(t(j)-1), if j-nl<= i <= j;
k*(t(j))*(s(i)-1), if j < i <= j+nu,
where s(i) = i/(n+1), t(j) = j/(n+1) and k = 1/(n+1).
ARPACK Authors
Richard Lehoucq
Danny Sorensen
Chao Yang
Dept. of Computational & Applied Mathematics
Rice University
Houston, Texas
*/
#ifndef BNMATRXW_H
#define BNMATRXW_H
template<class ARFLOAT>
void MatrixW(int n, int nl, int nu, ARFLOAT* &A)
{
int i, j, p;
ARFLOAT h;
// Defining h.
h = 1.0/ARFLOAT(n+1);
// Creating output vector A.
A = new ARFLOAT[n*(nl+nu+1)];
p = 0;
for (j=1; j<=n; j++) {
for (i=j-nu; i<=j; i++) {
if (i<1) {
A[p++] = 0.0;
}
else {
A[p++] = h*(ARFLOAT(j)*h-1.0)*(ARFLOAT(i)*h);
}
}
for(i=j+1; i<=(j+nl); i++) {
if (i>n) {
A[p++] = 0.0;
}
else {
A[p++] = h*(ARFLOAT(i)*h-1.0)*(ARFLOAT(j)*h);
}
}
}
} // MatrixW.
#endif // BNMATRXW_H
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