--- a
+++ b/featurebased-approach/subfunctions/lib/Recurrence quantification analysis (RQA)/RPplot.m
@@ -0,0 +1,101 @@
+function [RP,DD] = RPplot(P,m,t,r,index)
+
+%  Recurrence plot (RP) with fixed threshold value 
+
+%  Input:   P: time series;
+%           m: the embedding dimension
+%           t: the delay time
+%           r: the threshold value 
+%           index: the value 0 or 1 (0 for Euclidean distance,1 for maximum distance)
+% Output: 
+%           RP:  Recurrence plot Matrix
+%           DD:  Distance Matrix          
+
+%  referrence: 
+%  X Li, G Ouyang, X Yao, X Guan, Dynamical characteristics of pre-epileptic seizures in rats with recurrence quantification analysis
+%  Physics Letters A 333 (1), 164-171
+
+%%  If you need these codes that implement critical functions with (fast) C code, please visit my website:
+%%  http://www.escience.cn/people/gxouyang/Tools.html
+
+%  revise time: May 5 2014, Ouyang,Gaoxiang
+%  Email: ouyang@bnu.edu.cn
+%  
+%  Example:
+% P = randn(1,100);
+% [RP,DD] = RPplot(P,3,1,.5,0);
+% subplot(121);imagesc(RP)
+% P = sin(0.1:0.1:10);
+% [RP,DD] = RPplot(P,3,1,.5,0);
+% subplot(122);imagesc(RP)
+%
+% Copyright (c) 2014, Gaoxiang Ouyang
+%All rights reserved.
+%
+%Redistribution and use in source and binary forms, with or without
+%modification, are permitted provided that the following conditions are
+%met:
+%
+%    * Redistributions of source code must retain the above copyright
+%      notice, this list of conditions and the following disclaimer.
+%    * Redistributions in binary form must reproduce the above copyright
+%      notice, this list of conditions and the following disclaimer in
+%      the documentation and/or other materials provided with the distribution
+%
+%THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+%AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+%IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+%ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+%LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+%CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+%SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+%INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+%CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+%ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+%POSSIBILITY OF SUCH DAMAGE.
+
+r = r*std(P);
+
+if nargin < 4, error('Not enough input arguments'),end
+N=length(P);
+
+X=zeros(N-(m-1)*t,m);
+for k=1:(N-(m-1)*t)
+    PP=[];
+    for i=1:m
+        PP=[PP P(1,k-t+i*t)];
+    end
+    X(k,:)=PP;
+end
+N1=length(X);
+
+DD=zeros(N1,N1);
+if index == 0;
+    r = r*r;
+    for k1=1:N1 
+       for k2=k1+1:N1
+           DD(k1,k2) = sum( (X(k1,:) - X(k2,:)).^2 );
+       end
+     end
+    DD=DD+DD';
+end
+
+if index == 1
+    for k1=1:N1       
+        for k2=k1+1:N1
+            DD(k1,k2) = max(abs(X(k1,:)-X(k2,:)));
+        end
+    end
+    DD=DD+DD';
+end
+
+RP=zeros(N1,N1);
+for i=1:N1       
+    for j=i+1:N1
+        if DD(i,j) <= r
+            RP(i,j)=1;
+            RP(j,i)=1;
+        end
+    end
+end
+RP = RP +eye(N1);
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