VecStrideNorm

Computes the norm of subvector of a vector defined by a starting point and a stride.

Synopsis

int VecStrideNorm(Vec v,int start,NormType ntype,double *norm)
Collective on Vec

Input Parameter

v - the vector
start - starting point of the subvector (defined by a stride)
ntype - type of norm, one of NORM_1, NORM_2, NORM_INFINITY

Output Parameter

norm -the norm

Notes

One must call VecSetBlockSize() before this routine to set the stride information.

If x is the array representing the vector x then this computes the norm of the array (x[start],x[start+stride],x[start+2*stride], ....)

This is useful for computing, say the norm of the pressure variable when the pressure is stored (interlaced) with other variables, say density etc.

This will only work if the desire subvector is a stride subvector

Keywords

vector, subvector norm, norm

See Also

VecNorm(), VecStrideGather(), VecStrideScatter(), VecStrideMin(), VecStrideMax()

Examples

src/vec/examples/tutorials/ex11f.F
src/vec/examples/tutorials/ex11.c

Level:advanced
Location:src/vec/utils/vinv.c
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