public class Dppequ
- extends java.lang.Object
Following is the description from the original
Fortran source. For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
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* DPPEQU computes row and column scalings intended to equilibrate a
* symmetric positive definite matrix A in packed storage and reduce
* its condition number (with respect to the two-norm). S contains the
* scale factors, S(i)=1/sqrt(A(i,i)), chosen so that the scaled matrix
* B with elements B(i,j)=S(i)*A(i,j)*S(j) has ones on the diagonal.
* This choice of S puts the condition number of B within a factor N of
* the smallest possible condition number over all possible diagonal
* UPLO (input) CHARACTER*1
* = 'U': Upper triangle of A is stored;
* = 'L': Lower triangle of A is stored.
* N (input) INTEGER
* The order of the matrix A. N >= 0.
* AP (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)
* The upper or lower triangle of the symmetric matrix A, packed
* columnwise in a linear array. The j-th column of A is stored
* in the array AP as follows:
* if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
* if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
* S (output) DOUBLE PRECISION array, dimension (N)
* If INFO = 0, S contains the scale factors for A.
* SCOND (output) DOUBLE PRECISION
* If INFO = 0, S contains the ratio of the smallest S(i) to
* the largest S(i). If SCOND >= 0.1 and AMAX is neither too
* large nor too small, it is not worth scaling by S.
* AMAX (output) DOUBLE PRECISION
* Absolute value of largest matrix element. If AMAX is very
* close to overflow or very close to underflow, the matrix
* should be scaled.
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* > 0: if INFO = i, the i-th diagonal element is nonpositive.
* .. Parameters ..
|Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
public static void dppequ(java.lang.String uplo,