NormType#

Synopsis#

typedef enum {
  NORM_1         = 0,
  NORM_2         = 1,
  NORM_FROBENIUS = 2,
  NORM_INFINITY  = 3,
  NORM_1_AND_2   = 4
} NormType;

Values#

• NORM_1 - the one norm, $||v|| = \sum_i | v_i |$. $||A|| = \max_j || A_{*j} ||$, maximum column sum

• NORM_2 - the two norm, $||v|| = sqrt(\sum_i |v_i|^2)$ (vectors only)

• NORM_FROBENIUS - $||A|| = sqrt(\sum_{ij} |A_{ij}|^2)$, same as NORM_2 for vectors

• NORM_INFINITY - $||v|| = \max_i |v_i|$. $||A|| = \max_i || A_{i*} ||_1$, maximum row sum

• NORM_1_AND_2 - computes both the 1 and 2 norm of a vector. The values are stored in two adjacent PetscReal memory locations

Note#

The v above represents a Vec while the A represents a Mat

See Also#

Vectors and Parallel Data, Vec, Mat, VecNorm(), VecNormBegin(), VecNormEnd(), MatNorm(), NORM_1, NORM_2, NORM_FROBENIUS, NORM_INFINITY, NORM_1_AND_2, ReductionType

Level#

beginner

Location#

include/petscvec.h

Examples#

src/tao/tutorials/ex4.c

Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages