naginterfaces.library.sort.realvec_​rank_​rearrange

naginterfaces.library.sort.realvec_rank_rearrange(rv, m1, irank)

realvec_rank_rearrange rearranges a vector of real numbers into the order specified by a vector of ranks.

For full information please refer to the NAG Library document for m01ea

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/m01/m01eaf.html

Parameters

rvfloat, array-like, shape $\left(\text{m2}\right)$

Elements $m1-1$ to $\text{m2}-1$ of $rv$ must contain real values to be rearranged.

m1int

Note: this argument represents an array index; the value you supply must be base-1 for compatibility with the NAG Engine.

$m1$ and $\text{m2}$ must specify the range of the ranks supplied in $irank$ and the elements of $rv$ to be rearranged.

irankint, array-like, shape $\left(\text{m2}\right)$

Elements $m1-1$ to $\text{m2}-1$ of $irank$ must contain a permutation of the integers $m1$ to $\text{m2}$, which are interpreted as a vector of ranks.

Returns

rvfloat, ndarray, shape $\left(\text{m2}\right)$

These values are rearranged into rank order. For example, if $irank[i-1]=m1$, then the initial value of $rv[i-1]$ is moved to $rv[m1-1]$.

irankint, ndarray, shape $\left(\text{m2}\right)$

Used as internal workspace prior to being restored and hence is unchanged.

Raises

NagValueError

(errno $1$)

On entry, $m1=⟨value⟩$ and $\text{m2}=⟨value⟩$.

Constraint: $m1\le \text{m2}$.

(errno $1$)

On entry, $m1=⟨value⟩$.

Constraint: $m1\ge 1$.

(errno $1$)

On entry, $\text{m2}=⟨value⟩$.

Constraint: $\text{m2}\ge 1$.

(errno $2$)

$irank[m1:\text{m2}-1]$ does not contain a permutation of the integers $m1$ to $\text{m2}$. $irank[I-1]$ contains an out-of-range value: $I=⟨value⟩$, $irank[I-1]=⟨value⟩$.

(errno $3$)

$irank[m1:\text{m2}-1]$ does not contain a permutation of the integers $m1$ to $\text{m2}$. $irank$ contains a repeated value: $⟨value⟩$.

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

realvec_rank_rearrange is designed to be used typically in conjunction with the ranking functions realvec_rank(), intvec_rank(), charvec_rank(), realmat_rank_rows(), intmat_rank_rows(), realmat_rank_columns(), intmat_rank_columns() and arbitrary_rank(). After one of those functions has been called to determine a vector of ranks, realvec_rank_rearrange can be called to rearrange a vector of real numbers into the rank order. If the vector of ranks has been generated in some other way, then permute_check() should be called to check its validity before realvec_rank_rearrange is called.