How to trim start and end of time series data?

44 次查看（过去 30 天）
Haya Ali
Haya Ali 2023-3-10
回答： Sulaymon Eshkabilov 2023-3-10
I have 234 points in a signal. I want to trim the start and end of the reconstructed signal i.e. I want to start the signal from 100 and end it at 200. How can I do that in my present signal? Below is my code. Please help
close all; clear all; clc;
X1= [0.978184526233207
1.09489935704680
1.59164669497844
1.04748369986280
0.333456859419425
-0.776374729851942
-1.77654791200448
-1.48977341070183
-1.19560578883582
-0.216216169866790
-0.669130828272027
-0.176959953605121
-0.970038307444731
-1.46480552961072
-1.62008734051190
-0.869510428389788
-0.583273608934337
0.177196159526092
-0.446730619635104
-0.228742243963847
0.203025211047556
0.503354882236360
1.39271941057077
1.64866067380047
1.19038693126125
1.03363708342700
0.424041450386524
0.439260802070332
0.600343029025588
-0.0306738251258923
0.0958539085936714
1.14918362652028
1.15391408947321
0.898540503972080
0.0472213466344582
0.00554562959786900
0.102035244743441
-0.249504759613057
-0.143324794565285
-0.0607968027841552
-0.339183146089067
-0.371455075889551
-0.160251860132050
0.132393073200215
0.938710469108145
0.239353883527975
0.185569511807904
-0.370020642471384
-0.996994900124399
-1.57174260492213
-1.48675651948153
-0.499165159505607
0.000116451587039918
0.246101189551887
0.409185790688870
-0.0313952638414288
-0.213801932159108
0.597498268609943
1.23024780780428
1.50500323997789
1.23638364680667
0.174718173502008
-0.937779454147309
-1.85031898085982
-1.68634602636543
-1.11070366695686
0.171444432824592
0.178524883821887
0.686946348939107
0.405014944526230
0.0489364761057079
-0.253870961209884
-0.187277641813404
-0.442643912693939
-0.653848117914339
-0.760214986268639
-1.31958071983592
-0.992551625949963
-1.48794872511749
-1.33879258050990
-0.856793441452986
-0.394408939345198
-0.589006703594641
-0.274862175225194
0.505079986687640
1.34603779666379
1.76719242084883
1.65796553032041
0.860392149042695
0.184734489994875
-0.791575725714462
-0.833021834564249
-0.233540847901951
0.438051905752895
0.719888942815665
1.06399332034039
0.974754245290287
0.266984272303734
-0.729320359247078
-0.744243620482325
-0.575839769213132
0.0342930803324412
0.431341625822876
1.56474643785566
1.66219038781816
1.07628705674092
0.00960040748809378
-1.26146670726756
-1.52472663287358
-1.26960375489921
-0.888750005807918
-0.320150534790412
1.19137773775656
1.18652374319566
0.757841690371203
-0.0812900199662216
-0.0737080084875141
-0.00367152998326807
-0.593387210797996
-0.740736628261915
-1.58669360678985
-1.54377485379439
-1.84344656563496
-1.15165538472024
-0.315439395511712
0.426080088299539
0.789262136299863
0.825390061142108
0.533927504032497
0.840270169210173
1.07231276429206
0.866660909031804
1.05499421128736
0.544246693106188
0.554892764190835
-0.125091702012162
-0.523958216708689
-0.471186093739212
-0.553505176240973
-0.471307834890186
0.255329511361375
0.443309968999109
0.531847363093168
0.539542288619972
0.531750081585950
0.483862231580577
0.945027379981078
1.16191571414102
0.886509781337565
1.45760913993651
1.74023166218482
1.45663110914463
1.37108609639611
0.927232494902915
0.677582600687758
0.828772608717250
-0.373156343165001
-0.897734171971235
-1.60272592455266
-2.74488192175295
-2.49310365976706
-1.30600932183767
-0.941072129426888
-0.0396666293298666
-0.000401990182564594
-0.747846741547528
-0.680077890685762
-0.345780729985813
0.226661747742711
1.37118037611648
1.27715094683531
0.463525878733334
-1.51526557898599
-2.67957880739113
-2.27925321917559
-1.62970884714424
-0.376263330231145
0.382687307404915
1.52808206930792
1.86628419456866
1.72842389966317
2.18592865006880
1.16364807188454
1.16043750739135
-0.191998864325526
-1.17989059055431
-1.40988398765226
-0.493116315847491
-0.727759810617587
-0.0581583652355533
0.199079551212408
-0.499029369075121
-0.694837778241995
-1.40316718622795
-0.360060349926195
1.07629252223562
2.30376353398820
2.19754776326396
1.82079414479445
1.03315969900616
0.491810249519456
-0.270410080497886
0.135118355485126
-0.101090351581757
-0.409845945421996
-0.839294673539560
-1.67123093873688
-1.48346638597601
-0.410737203021099
0.740659198972951
0.293016252080021
-1.10619719722397
-1.18664316827541
-1.12945427532509
-0.671918631269854
-0.287947673491579
-0.335792016783277
-0.587386687196651
-1.20431179904573
-0.669980798921371
-0.516398365917139
0.394277956967727
1.21512353239220
0.216692421479053
0.101783706338712
0.335111404288256
0.00107923844629068
-0.0104442258803883
0.957259068184531
1.50031210278973
1.84064040172912
0.364645903950982
-0.731000570030488
0.176413750203213];
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Addnum1=10;%Num1er of additional data points in each time interval.
N1=Addnum1*length(X1); %Length of the reconstructed signal(the continuous signal);
Rec1=zeros([1,N1]);
Rate1=zeros([1,N1]);
nx1=zeros([1,N1]);
NX1=zeros([1,length(X1)]);
zeroline1=zeros([1,N1]);
index=0;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=1:N1
if mod(i,Addnum1)==1
index=index+1;
NX1(index)=i;
end
nx1(i)=i;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=1:N1
Rec1(i)=0;
Rate1(i)=0;
for j=1:length(X1)
Rec1(i)=Rec1(i)+X1(j)*sinc((1/Addnum1)*(i-Addnum1*(j-1)));
Rate1(i)=Rate1(i)+X1(j)*(cos((pi/Addnum1)*(i-Addnum1*(j-1)))/(i-Addnum1*(j-1))-sin((pi/Addnum1)*(i-Addnum1*(j-1)))/((pi/Addnum1)*(i-Addnum1*(j-1))^2));
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
mean_X1=mean(X1);
X1=X1-mean_X1;
mean_Rec1=mean(Rec1);
Rec1=Rec1-mean_Rec1;
figure
plot(nx1,Rec1,'sg');
hold on
plot(nx1,zeroline1,'k');
plot(nx1,Rate1,'*b');
plot(NX1,X1,'or')
legend ('Reconstructed Signal X1','zeroline1','Rate Signal X1','BOLD Signal X1')

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采纳的回答

Sulaymon Eshkabilov
Ran in:
Here is how it can be done using an index option:
X1 = [0.978184526233207
1.09489935704680
1.59164669497844
1.04748369986280
0.333456859419425
-0.776374729851942
-1.77654791200448
-1.48977341070183
-1.19560578883582
-0.216216169866790
-0.669130828272027
-0.176959953605121
-0.970038307444731
-1.46480552961072
-1.62008734051190
-0.869510428389788
-0.583273608934337
0.177196159526092
-0.446730619635104
-0.228742243963847
0.203025211047556
0.503354882236360
1.39271941057077
1.64866067380047
1.19038693126125
1.03363708342700
0.424041450386524
0.439260802070332
0.600343029025588
-0.0306738251258923
0.0958539085936714
1.14918362652028
1.15391408947321
0.898540503972080
0.0472213466344582
0.00554562959786900
0.102035244743441
-0.249504759613057
-0.143324794565285
-0.0607968027841552
-0.339183146089067
-0.371455075889551
-0.160251860132050
0.132393073200215
0.938710469108145
0.239353883527975
0.185569511807904
-0.370020642471384
-0.996994900124399
-1.57174260492213
-1.48675651948153
-0.499165159505607
0.000116451587039918
0.246101189551887
0.409185790688870
-0.0313952638414288
-0.213801932159108
0.597498268609943
1.23024780780428
1.50500323997789
1.23638364680667
0.174718173502008
-0.937779454147309
-1.85031898085982
-1.68634602636543
-1.11070366695686
0.171444432824592
0.178524883821887
0.686946348939107
0.405014944526230
0.0489364761057079
-0.253870961209884
-0.187277641813404
-0.442643912693939
-0.653848117914339
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-1.31958071983592
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-1.33879258050990
-0.856793441452986
-0.394408939345198
-0.589006703594641
-0.274862175225194
0.505079986687640
1.34603779666379
1.76719242084883
1.65796553032041
0.860392149042695
0.184734489994875
-0.791575725714462
-0.833021834564249
-0.233540847901951
0.438051905752895
0.719888942815665
1.06399332034039
0.974754245290287
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0.0342930803324412
0.431341625822876
1.56474643785566
1.66219038781816
1.07628705674092
0.00960040748809378
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1.19137773775656
1.18652374319566
0.757841690371203
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-0.593387210797996
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0.426080088299539
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1.07231276429206
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0.443309968999109
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0.539542288619972
0.531750081585950
0.483862231580577
0.945027379981078
1.16191571414102
0.886509781337565
1.45760913993651
1.74023166218482
1.45663110914463
1.37108609639611
0.927232494902915
0.677582600687758
0.828772608717250
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0.382687307404915
1.52808206930792
1.86628419456866
1.72842389966317
2.18592865006880
1.16364807188454
1.16043750739135
-0.191998864325526
-1.17989059055431
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-0.493116315847491
-0.727759810617587
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0.199079551212408
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-1.40316718622795
-0.360060349926195
1.07629252223562
2.30376353398820
2.19754776326396
1.82079414479445
1.03315969900616
0.491810249519456
-0.270410080497886
0.135118355485126
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-0.839294673539560
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-1.48346638597601
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0.740659198972951
0.293016252080021
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-0.587386687196651
-1.20431179904573
-0.669980798921371
-0.516398365917139
0.394277956967727
1.21512353239220
0.216692421479053
0.101783706338712
0.335111404288256
0.00107923844629068
-0.0104442258803883
0.957259068184531
1.50031210278973
1.84064040172912
0.364645903950982
-0.731000570030488
0.176413750203213];
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Range = 100:200;
X1 = X1(Range); % Range
Addnum1=10;%Num1er of additional data points in each time interval.
N1=Addnum1*length(X1); %Length of the reconstructed signal(the continuous signal);
Rec1=zeros([1,N1]);
Rate1=zeros([1,N1]);
nx1=zeros([1,N1]);
NX1=zeros([1,length(X1)]);
zeroline1=zeros([1,N1]);
index=0;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=1:N1
if mod(i,Addnum1)==1
index=index+1;
NX1(index)=i;
end
nx1(i)=i;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=1:N1
Rec1(i)=0;
Rate1(i)=0;
for j=1:length(X1)
Rec1(i)=Rec1(i)+X1(j)*sinc((1/Addnum1)*(i-Addnum1*(j-1)));
Rate1(i)=Rate1(i)+X1(j)*(cos((pi/Addnum1)*(i-Addnum1*(j-1)))...
/(i-Addnum1*(j-1))-sin((pi/Addnum1)*(i-Addnum1*(j-1)))/((pi/Addnum1)*(i-Addnum1*(j-1))^2));
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
mean_X1=mean(X1);
X1=X1-mean_X1;
mean_Rec1=mean(Rec1);
Rec1=Rec1-mean_Rec1;
figure
plot(nx1,Rec1,'sg');
hold on
plot(nx1,zeroline1,'k');
plot(nx1,Rate1,'*b');
plot(NX1,X1,'or')
legend ('Reconstructed Signal X1','zeroline1','Rate Signal X1','BOLD Signal X1')
axis tight

更多回答（2 个）

Arka
Arka 2023-3-10
Hi,
You can use array subscripting using the colon operator to achieve what you require.
In general, if you want to extract data from ith index to jth index, you can achieve that by doing so:
extracted = array(i:j);
So, in your case, to get the data from 100th index to 200th index, you can do:
extracted = Rec1(100:200);
If you wish to learn more about the colon operator, please go through the MathWorks documentation link below:
https://www.mathworks.com/help/matlab/ref/colon.html
Sarvesh Kale
Sarvesh Kale 2023-3-10
Hi Haya Ali ,
If you only want the reconstructed signal to start from 100th index to 200 index juts use indexing for that, from your code I think Rec1 is the reconstructed signal, example code
x1 = Rec1(100:200); % get entries from 100 to 200
t = nx1(100:200) ;
plot(nx1,Rec1)
I hope I understood your question and this helps your query

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