pucicu / rp

MATLAB scripts to create recurrence plots and to perform recurrence quantification analysis.

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Recurrence Plot & Quantification

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Simple MATLAB functions for calculating recurrence plots and recurrence quantification.

Functions

EMBED

Creates embedding vector using time delay embedding.

Syntax

Y=EMBED(X,M,T) creates the embedding vector Y from the time series X using a time delay embedding with dimension M and delay T. The resulting embedding vector has length N-T*(M-1), where N is the length of the original time series.

Reference

  • Packard, N. H., Crutchfield, J. P., Farmer, J. D., Shaw, R. S. (1980). Geometry from a time series. Physical Review Letters 45, 712-716.

Example

N = 300; % length of time series
x = .9*sin((1:N)*2*pi/70); % exemplary time series
y = embed(x,2,17); % embed into 2 dimensions using delay 17
plot(y(:,1),y(:,2))

RP

Calculates a recurrence plot.

Syntax

R=RP(X,E,THRESH,NORM,ALG) calculates the recurrence plot R from an embedding vector X and using the threshold E. X is a N-by-M matrix corresponding to N time points and M embedding dimensions.

[R,D]=RP(...) outputs the recurrence plot R and the underlying distance matrix D.

Optional arguments:

NORM - is a string setting the norm for distance calculation in phasespace. Can be 'euc' for euclidian norm (default) or 'max' for maximum norm.

ALG - is a string specifying the algorithm of calculating the distance matrix. Can be 'loops', 'vector' (default), or 'matlabvector'.

THRESH - is a string that specifies how the threshold epsilon will be calculated. With 'fix' (default) the RP is computed with a fixed threshold epsilon specified by the input parameter E. With 'var' the RP is computed with a fixed threshold epsilon, which corresponds to the lower 'E'-quantile (specified by E) of the distance distribution of all points in phasespace. With 'fan' the RP is computed with a variable threshold resulting in a fixed amount of nearest neighbours in phasespace, specified % by the fraction E of recurrence points

Reference

  • Marwan, N., Romano, M. C., Thiel, M., Kurths, J. (2007). Recurrence plots for the analysis of complex systems. Physics Reports, 438, 237-329.
  • Kraemer, K. H., Donner, R. V., Heitzig, J., & Marwan, N. (2018). Recurrence threshold selection for obtaining robust recurrence characteristics in different embedding dimensions. Chaos, 28, 085720.

Example

N = 300; % length of time series
x = .9*sin((1:N)*2*pi/70); % exemplary time series
xVec = embed(x,2,17); % embed into 2 dimensions using delay 17
R = rp(xVec,.1,'fix','max'); % calculate RP using maximum norm and fixed threshold
imagesc(R)

RQA

Calculates recurrence quantification analysis.

Syntax

Q=RQA(R,L,T) calculates measures of recurrence quantification analysis for recurrence plot R using minimal line length L and a Theiler window `T.

Output:

  • Y(1) = RR (recurrence rate)
  • Y(2) = DET (determinism)
  • Y(3) = <L> (mean diagonal line length)
  • Y(4) = Lmax (maximal diagonal line length)
  • Y(5) = ENTR (entropy of the diagonal line lengths)
  • Y(6) = LAM (laminarity)
  • Y(7) = TT (trapping time)
  • Y(8) = Vmax (maximal vertical line length)
  • Y(9) = RTmax (maximal white vertical line length)
  • Y(10) = T2 (recurrence time of 2nd type)
  • Y(11) = RTE (recurrence time entropy, i.e., RPDE)
  • Y(12) = Clust (clustering coefficient)
  • Y(13) = Trans (transitivity)

Reference

  • Marwan, N., Romano, M. C., Thiel, M., Kurths, J. (2007). Recurrence plots for the analysis of complex systems. Physics Reports, 438, 237-329.
  • Marwan, N., Donges, J. F., Zou, Y., Donner, R. V., Kurths, J. (2009). Complex network approach for recurrence analysis of time series. Physics Letters A, 373, 4246-4254.

Example

N = 300; % length of time series
x = .9*sin((1:N)*2*pi/70); % exemplary time series
xVec = embed(x,2,17);
R = rp(xVec,.1);
Y = rqa(R);

RP_ISO

Calculates the isodirectional recurrence plot

Syntax

R=RP_ISO(X,E,W) calculates the isodirectional recurrence plot R from an embedding vector X and using the threshold E for the vector distances and threshold W for the angle to be considered as isodirectional.

R=RP_ISO(X,E,W,TAU) estimates tangential vector using time delay TAU.

Example

[t x] = ode45('lorenz',[0 100],[-6.2 -10 14]);
[R1, SP, R0] = rp_iso(x(3000:5000,:),10,.2);

nexttile
imagesc(R0) % regular RP
axis square

nexttile
imagesc(R1) % isodirectional RP
axis square

RP_PERP

Calculates the perpendicular recurrence plot

Syntax

R=RP_PERP(X,E,W) calculates the perpendicular recurrence plot R from an embedding vector X and using the threshold E for the vector distances and threshold W for the angle to be considered as perpendicular.

R=RP_PERP(X,E,W,TAU) estimates tangential vector using time delay TAU (works only if condition in line 95 is set to 0).

Example

[t x] = ode45('lorenz',[0 100],[-6.2 -10 14]);
[R1, SP, R0] = rp_perp(x(3000:5000,:),10,.25);

nexttile
imagesc(R0) % regular RP
axis square

nexttile
imagesc(R1) % perpendicular RP
axis square

Application

Part of this code was used in the study

  • M. H. Trauth, A. Asrat, W. Duesing, V. Foerster, K. H. Kraemer, N. Marwan, M. A. Maslin, F. Schaebitz: Classifying past climate change in the Chew Bahir basin, southern Ethiopia, using recurrence quantification analysis, Climate Dynamics, 53(5), 2557–2572 (2019). DOI:10.1007/s00382-019-04641-3

How to cite

Background

read more about recurrence plot analysis at http://www.recurrence-plot.tk/

License

(see LICENSE file)

Copyright 2016-2020, Potsdam Institute for Climate Impact Research (PIK), Institute of Geosciences, University of Potsdam, K. Hauke Kraemer, Norbert Marwan, Martin H. Trauth

About

MATLAB scripts to create recurrence plots and to perform recurrence quantification analysis.

License:GNU Affero General Public License v3.0


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