## RQA

Specific discussion regarding applications.
sultornsanee
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Joined: Tue Oct 12, 2010 21:05
Affiliation (Univ., Inst., Dept.): Northeastern University
Location: Boston, Massachusetts, USA
Research field: Pattern Recognition Analysis
Location: Network/Nano Science and Engineering Laboratory, Northeastern University, Boston, USA

### RQA

After I create recurrence matrix using "crp" function and I get a recurrence matrix, can I calculate RQA from this matrix?

I read your manual but it seems all function needed "time series" as input.
Sivarit Sultornsanee (Tony)

Network/Nano Science and Engineering Laboratory (NSE Lab)
360 Huntington Ave., Room 320 SN, Boston, MA 02038, USA
E-mail: SULTORNSANEE.S@HUSKY.NEU.EDU

Norbert
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Joined: Wed Jan 4, 2006 11:03
Affiliation (Univ., Inst., Dept.): Potsdam Institute for Climate Impact Research, Germany
Location: Potsdam, Germany
Location: Potsdam Institute for Climate Impact Research, Germany

### Re: RQA

yes, you can do it. for example:

Code: Select all

``````% create recurrence plot
X = crp(timeseries,'silent');

% get distributions of line lengths
% (actually you should apply here the Theiler window before, but I omit it for simplification)
[m l] = dl(X); % l is a list of all line lengths of diagonal lines
[m v] = tt(X); % v is a list of all line lengths of vertical lines

% recurrence rate
mean(X(:))

% determinism
sum(l(l>=lmin))/sum(X(:)) % where lmin is the minimal diagonal line length, e.g. lmin=2

% mean diagonal line length
mean(l(l>=lmin))

% maximal diagonal line length
max(l(l>=lmin))

% entropy
histL=hist(l,1:length(X));
entropy(histL(:));
``````
for the vertical line based measures (laminarity, trapping time etc.) just use vector v instead of l

best
norbert

sultornsanee
Senior
Posts: 29
Joined: Tue Oct 12, 2010 21:05
Affiliation (Univ., Inst., Dept.): Northeastern University
Location: Boston, Massachusetts, USA
Research field: Pattern Recognition Analysis
Location: Network/Nano Science and Engineering Laboratory, Northeastern University, Boston, USA

### Re: RQA

Thank you very much ... I will try to test your codes.
Sivarit Sultornsanee (Tony)

Network/Nano Science and Engineering Laboratory (NSE Lab)
360 Huntington Ave., Room 320 SN, Boston, MA 02038, USA
E-mail: SULTORNSANEE.S@HUSKY.NEU.EDU

Parri-Dee
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