# runindex

Versione 3.1.2 (2,55 KB) da
linear indices for each run in a vector (run length encoding, and decoding)
Aggiornato 8 feb 2019

Visualizza la licenza

For a vector V, I = runindex(V) returns a vector I of the same size as
V with linear indices per run within V. Runs are contiguous sequences
of one value for one or more consecutive elements in V.

Example:
% create a vector with four runs: 3x20, 2x4, 4x55, 1x999
V = [20 20 20 4 4 55 55 55 55 999]
I = runindex(V)
% [ 1 2 3 1 2 1 2 3 4 1]

[I, RLE] = rundindex(V) also returns a run length encoding of V in
the N-by-3 array RLE. Each row is a run, with the value in the first
column, the start index in the second column, and the run length in
the third column. N is the number of runs.

V = [8 7 7 7 3 3 12 12 12 12]
[~, RLE] = runindex(V)
% RLE =
% 8 1 1
% 7 2 3
% 3 5 2
% 12 7 4

When given two input vectors U and C, V = runindex(U, C) decodes the
vectors U (values) and C (counts) into the vector V. V is the
concatenation of all values of U, where the k-th value U(k) is
repeated C(k) times. V is a sum(C)-by-1 column vector. When C(k) is 0,
U(k) is omitted from the vector.
[V, RLE] = runindex(U, C) returns the run-length encoding of V in RLE.

V = runindex([5 10 99], [2 1 3])
% V = [5 5 10 99 99 99]

Vin = [1 1 2 2 1 1 1]
[I, RLE] = runindex(Vin) % encoding
% I = [1 2 1 2 1 2 3]
Vout = runindex(RLE(:,1), RLE(:,3)) % decoding
% Vout equals Vin

V = runindex([0 1 0 2], [2 3 1 4])
% V = [0 0 1 1 1 0 2 2 2 2]) ;

Notes
- This function is related to run-length encoding:
https://en.wikipedia.org/wiki/Run-length_encoding

### Cita come

Jos (10584) (2024). runindex (https://www.mathworks.com/matlabcentral/fileexchange/56131-runindex), MATLAB Central File Exchange. Recuperato .

##### Compatibilità della release di MATLAB
Creato con R2017b
Compatibile con qualsiasi release
##### Compatibilità della piattaforma
Windows macOS Linux
##### Categorie
Scopri di più su Arithmetic Operations in Help Center e MATLAB Answers
##### Riconoscimenti

Ispirato da: RunLength

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!
Versione Pubblicato Note della release
3.1.2

fixed small mistake in the help

3.1.1

new image

3.1

new image

3.0.0.0