Search found 199 matches

by Norbert
Mon Aug 29, 2016 14:47
Forum: General Discussion
Topic: CRP Toolbox for Visual Fixations - Set Threshold?
Replies: 1
Views: 27598

Re: CRP Toolbox for Visual Fixations - Set Threshold?

Hi,

you have to use the 'nonorm' option in the crp-function, e.g.,

Code: Select all

r = crp2(data,m,tau,10,'nonorm');
Best wishes
Norbert
by Norbert
Wed Jul 13, 2016 08:17
Forum: Recurrence Plot Symposium
Topic: Minisymposium on Recurrence Plots at the PNLD2016
Replies: 0
Views: 49217

Minisymposium on Recurrence Plots at the PNLD2016

We are organizing a Minisymposium on Recurrence Plots at the conference "Perspectives in Nonlinear Dynamics" (PNLD2016) in Berlin, July 24th–29th, 2016. The programm is now online: http://pnld2016.physik.hu-berlin.de/node/21
by Norbert
Wed Jul 13, 2016 08:14
Forum: Bugs
Topic: Bug in Crqad.m
Replies: 1
Views: 26416

Re: Bug in Crqad.m

Hi David, thanks for the bug report. Yes, you are completely right. This code was not used so much, therefore I missed to include this "normalization" option in this function (although in the help text it is stated that this would work). I have now fixed this problem (R30.5). crqad allows ...
by Norbert
Wed Jul 13, 2016 07:55
Forum: Available Software
Topic: Data file types for recurrence-plot.tk's online calculator
Replies: 1
Views: 25921

Re: Data file types for recurrence-plot.tk's online calculat

It is the most simple one. This means, an simple ASCII file with a column of numbers (or several columns).

Thanks for the hint. I will add a remark on the website.
by Norbert
Wed Jul 13, 2016 07:45
Forum: Applications
Topic: EEG
Replies: 11
Views: 175265

Re: EEG

I would be careful when using embedding. Do not overembed because it will cause artefacts (spurious correlations in the RP and artificially many long lines). Therefore, I would probably use a low embedding dimension and delay for all channels (e.g., m=3, tau = 2). Final values depend on the data. It...
by Norbert
Wed Jul 13, 2016 07:39
Forum: General Discussion
Topic: Threshold and Attractor diameter
Replies: 1
Views: 28335

Re: Threshold and Attractor diameter

(reply refers to the CRP Toolbox) It depends on the selected recurrence criterion. When it is a fixed size of the neighbourhood, such for EUC, MAX, MIN, then it is the absolute value of ε. But there are also "dynamical thresholds", such as selecting the fixed amount of nearest neighbours (...
by Norbert
Wed Jul 13, 2016 07:25
Forum: General Discussion
Topic: radius threshold
Replies: 2
Views: 32311

Re: radius threshold

Maybe let's start with the definition of the RP: Θ(ε–|| x ( i ) – x ( j )|| The threshold ε is just a scalar value. Its choice is somehow related to the value range of the time series or the diameter of the phase space. One way to relate ε to this value range or diameter is to have it as a certain f...
by Norbert
Mon Nov 16, 2015 10:23
Forum: Recurrence Plot Symposium
Topic: 7th Recurrence Plot Symposium in Brazil
Replies: 0
Views: 49049

7th Recurrence Plot Symposium in Brazil

The seventh international recurrence plot symposium will be at the Escola Politecnica (Universidade de Sao Paulo) in Sao Paulo, Brazil, in August 23-25, 2017.

More information:
http://symposium.recurrence-plot.tk/
by Norbert
Mon Nov 16, 2015 10:21
Forum: Available Software
Topic: Downloading the crp toolbox
Replies: 3
Views: 35320

Re: Downloading the crp toolbox

viniciusjdv wrote:Prof,

How can I use the crqa routine to extract the RQA measures based on a fixed recurrence rate (e.g. RR=5%)?
Simply using:

Code: Select all

crqa(data,m,tau,0.05,'rr')
by Norbert
Mon Nov 16, 2015 10:20
Forum: Available Software
Topic: Commandline Recurrence Plots
Replies: 4
Views: 38927

Re: Commandline Recurrence Plots

1) Is this threshold parameter an absolute value of the radius or a percentage value of the maximum diameter of the phase space? Yes, it is an absolute value. 2) Is there a way to vary the parameter m and t? I mean, instead of using "-m 3 -t 7", … Yes, you can do it. You have to use eithe...
by Norbert
Fri Sep 25, 2015 12:33
Forum: Bugs
Topic: Displayed fonts problem
Replies: 1
Views: 26270

Re: Displayed fonts problem

Hello,
cold you please post a screenshot and further details about your operatin system?
Thanks!
Norbert
by Norbert
Sat Aug 22, 2015 11:09
Forum: General Discussion
Topic: Calculating perpendicular RP
Replies: 1
Views: 29837

Re: Calculating perpendicular RP

In this case (tangential motion close to the LOI) you just need to apply the Theiler window. The CRP toolbox has such an option. Just look in the help of the crp and crqa functions.
by Norbert
Tue Jul 7, 2015 21:42
Forum: General Discussion
Topic: Confidence Intervals for RP-measures
Replies: 1
Views: 28009

Re: Confidence Intervals for RP-measures

Hi David, yes, Stefan's solution on the Humboldt university website is different. It relates to this paper: S. Schinkel, N. Marwan, O. Dimigen, J. Kurths: Confidence bounds of recurrence-based complexity measures, Physics Letters A, 373(26), 2245–2250 (2009). DOI:10.1016/j.physleta.2009.04.045 For t...
by Norbert
Tue Jul 7, 2015 21:37
Forum: General Discussion
Topic: correlation using probability of recurrence
Replies: 1
Views: 27128

Re: correlation using probability of recurrence

Hi, your solution looks correct. Perhaps the used time window is too small. You can add another argument that specifies the time window (i.e. the maximal time range that will be considered by this method). If you need the p(tau) separately, you can calculate them by the crqad function: y = crqad(tim...
by Norbert
Tue Jul 7, 2015 21:27
Forum: Quantification
Topic: Sample code to apply a windowing recurrence analysis with CR
Replies: 0
Views: 48129

Sample code to apply a windowing recurrence analysis with CR

I post here a MATLAB coding example that was developed within the hands-on session of the 6th RP symposium in Grenoble. It allows a windowed recurrence analysis with changing parameters for each window. %% Sample code to apply a windowing recurrence analysis with CRP Toolbox for MATLAB % Allows to c...