assignment problem in a for loop

Hello people, I have an assignment problem and I don't know how to solve.

clc;
clear;
close all;
%% Time structure
dt=0.01;          %sampling time
%% System structure
A = [1.02  -0.1
     0.1   0.98]; 
B = [0.5 0
    0.05 0.5];
G = [0.3 0
     0 0.3]; 
C = eye(2,2);
Qf = [50 0
      0 50];
%% MPC parameters
Q  = eye(2);
R  = eye(2)*50;
N = 5;
%% Building block matrices
I = eye(2,2);
q = 2;
m = 2;
Qbar = blkdiag(Q,Q,Q,Q,Qf,R,R,R,R);
Fq = blkdiag(sqrt(Q),sqrt(Q),sqrt(Q),sqrt(Q),sqrt(Q),sqrt(Qf),sqrt(R),sqrt(R),sqrt(R),sqrt(R),sqrt(R));
Gxx = zeros(2*N , size(A,1));
for i = 1:N
    Gxx(q*i-q+1:q*i , :) = A^i;
end
Gxu = zeros(2*N , 2*N);
for i = 1:N
   for j = 1:i
      Gxu(q*i-q+1:q*i , m*j-m+1:m*j) = A^(i-j)*(B); 
   end    
end
Gxw = zeros(2*N , 2*N);
for i = 1:N
    for j = 1:i
    Gxw(q*i-q+1:q*i , m*j-m+1:m*j) = A^(i-j)*(I);    
    end
end
%% Mean of u obtained from solver result
ubar1 = [-0.000581629157055178,-0.000581629156609152,-0.000581629281438909,-0.000581629281440897,-0.000581629281439613,-0.000581629281441646,-0.000581629281439253,-0.000581629281441243,-0.000581629283745490,-0.000581629284144206,131.400927231750,0,-43.5899689825575,-87.3447946140090,-0.121677240258015,-0.227961850128840,-0.0869533824650604,-0.130839304907035,-0.00960202231921041,-0.00960984528042930,0.0454701361380619,0.0690829738668646;-0.000528160807600932,-0.000528160806858417,-0.000528161014656819,-0.000528161014660146,-0.000528161014657446,-0.000528161014660808,-0.000528161014657155,-0.000528161014660429,-0.000528161018496181,-0.000528161019159948,218.736767442156,0,-72.5618189454592,-145.398065579508,-0.202155519406871,-0.379025814694336,-0.144353434705365,-0.217349689091955,-0.0155478255728175,-0.0155653199308984,0.0761167937761455,0.115615840165787;-0.000464850276767520,-0.000464850276767507,-0.000464850276766848,-0.000464850276766868,-0.000464850276767458,-0.000464850276767449,-0.000464850276767172,-0.000464850276767166,-0.000464850276767130,-0.000464850276767136,-0.00464850251156834,0,0,0,0,0,0,0,0,0,0,0;-0.000422890131101226,-0.000422890131101213,-0.000422890131100429,-0.000422890131100414,-0.000422890131100958,-0.000422890131100997,-0.000422890131100708,-0.000422890131100690,-0.000422890131100695,-0.000422890131100693,-0.00422890107641037,0,0,0,0,0,0,0,0,0,0,0;-0.000348309691892651,-0.000348309691892663,-0.000348309691892179,-0.000348309691892155,-0.000348309691892598,-0.000348309691892604,-0.000348309691892381,-0.000348309691892382,-0.000348309691892379,-0.000348309691892380,-0.00348309672703811,0,0,0,0,0,0,0,0,0,0,0;-0.000317448440512582,-0.000317448440512563,-0.000317448440511949,-0.000317448440511982,-0.000317448440512401,-0.000317448440512368,-0.000317448440512166,-0.000317448440512180,-0.000317448440512168,-0.000317448440512169,0,-0.00317448422922303,0,0,0,0,0,0,0,0,0,0;-0.000231995660577032,-0.000231995660577031,-0.000231995660576716,-0.000231995660576710,-0.000231995660577010,-0.000231995660577012,-0.000231995660576852,-0.000231995660576864,-0.000231995660576856,-0.000231995660576843,-0.00231995647779437,0,0,0,0,0,0,0,0,0,0,0;-0.000211826109957114,-0.000211826109957123,-0.000211826109956741,-0.000211826109956731,-0.000211826109957007,-0.000211826109957004,-0.000211826109956862,-0.000211826109956874,-0.000211826109956863,-0.000211826109956857,-0.00211826098199697,0,0,0,0,0,0,0,0,0,0,0;-0.000115896358074462,-0.000115896358074466,-0.000115896358074303,-0.000115896358074301,-0.000115896358074452,-0.000115896358074453,-0.000115896358074381,-0.000115896358074372,-0.000115896358074371,-0.000115896358074375,-0.00115896351700854,0,0,0,0,0,0,0,0,0,0,0;-0.000106013267225743,-0.000106013267225713,-0.000106013267225495,-0.000106013267225514,-0.000106013267225653,-0.000106013267225657,-0.000106013267225582,-0.000106013267225581,-0.000106013267225585,-0.000106013267225582,-0.00106013261349873,0,0,0,0,0,0,0,0,0,0,0];
ubar2 = [-0.000581629151442759,-0.000581629150976575,-0.000581629281437736,-0.000581629281439817,-0.000581629281438418,-0.000581629281440531,-0.000581629281438100,-0.000581629281440181,-0.000581629283848340,-0.000581629284265049,65.9612196789050,0,0.0163528663340642,-0.0115687495095834,-21.9613299789049,-43.9177482522026,-0.0351465169397885,-0.0573268811696319,-0.00848969500416555,-0.0139375019482108,0.00936976354254012,0.0126783667337945;-0.000528160798780068,-0.000528160798005902,-0.000528161014654947,-0.000528161014658418,-0.000528161014655624,-0.000528161014659124,-0.000528161014655291,-0.000528161014658731,-0.000528161018657842,-0.000528161019349869,109.538144585391,0,0.0273450560748362,-0.0190569345422484,-36.4695717310723,-72.9307300429299,-0.0578364398062356,-0.0947345049761504,-0.0136866268276673,-0.0227458754979369,0.0159240204457714,0.0215664414794175;-0.000464850148258548,-0.000464850147797768,-0.000464850276739902,-0.000464850276742009,-0.000464850276740514,-0.000464850276742547,-0.000464850276740215,-0.000464850276742327,-0.000464850279122408,-0.000464850279534250,0,65.1932395076792,0.0163002305454987,-0.0113383082218456,-21.7054853369752,-43.4060306759143,-0.0346084968557704,-0.0565336465142243,-0.00832334193286985,-0.0137285737033249,0.00927132212395355,0.0125888175165625;-0.000422889917178537,-0.000422889916411515,-0.000422890131055573,-0.000422890131059036,-0.000422890131056160,-0.000422890131059569,-0.000422890131055833,-0.000422890131059312,-0.000422890135021385,-0.000422890135706981,0,108.524418821749,0.0273655844303290,-0.0185747423894637,-36.1317741553739,-72.2557401916522,-0.0572547780465873,-0.0938525774969211,-0.0134878862596612,-0.0224802718950870,0.0158385014160028,0.0213127948735551;-0.000348309691892901,-0.000348309691892894,-0.000348309691892164,-0.000348309691892170,-0.000348309691892627,-0.000348309691892591,-0.000348309691892341,-0.000348309691892409,-0.000348309691892398,-0.000348309691892359,-0.00348309672711165,0,0,0,0,0,0,0,0,0,0,0;-0.000317448440512921,-0.000317448440512929,-0.000317448440511979,-0.000317448440511974,-0.000317448440512384,-0.000317448440512391,-0.000317448440512184,-0.000317448440512162,-0.000317448440512158,-0.000317448440512165,0,0,0,-0.00317448422917531,0,0,0,0,0,0,0,0;-0.000231995660577191,-0.000231995660577196,-0.000231995660576725,-0.000231995660576713,-0.000231995660577007,-0.000231995660577007,-0.000231995660576840,-0.000231995660576861,-0.000231995660576864,-0.000231995660576847,-0.00231995647789305,0,0,0,0,0,0,0,0,0,0,0;-0.000211826109957367,-0.000211826109957373,-0.000211826109956736,-0.000211826109956738,-0.000211826109957001,-0.000211826109956983,-0.000211826109956865,-0.000211826109956888,-0.000211826109956864,-0.000211826109956847,-0.00211826098199371,0,0,0,0,0,0,0,0,0,0,0;-0.000115896358074550,-0.000115896358074549,-0.000115896358074301,-0.000115896358074296,-0.000115896358074455,-0.000115896358074451,-0.000115896358074373,-0.000115896358074376,-0.000115896358074373,-0.000115896358074374,-0.00115896351693273,0,0,0,0,0,0,0,0,0,0,0;-0.000106013267225860,-0.000106013267225836,-0.000106013267225499,-0.000106013267225518,-0.000106013267225656,-0.000106013267225653,-0.000106013267225577,-0.000106013267225580,-0.000106013267225585,-0.000106013267225581,0,0,0,0,0,0,0,0,0,0,-0.00106013261343957,0];
ubar3 = [-0.000581629145856014,-0.000581629145369818,-0.000581629281436549,-0.000581629281438723,-0.000581629281437267,-0.000581629281439437,-0.000581629281436938,-0.000581629281439131,-0.000581629283950715,-0.000581629284385333,0;-0.000528160790044915,-0.000528160789239457,-0.000528161014653141,-0.000528161014656719,-0.000528161014653785,-0.000528161014657422,-0.000528161014653464,-0.000528161014657056,-0.000528161018817937,-0.000528161019537960,0;-0.000464850142736338,-0.000464850142255738,-0.000464850276738761,-0.000464850276740947,-0.000464850276739355,-0.000464850276741506,-0.000464850276739047,-0.000464850276741207,-0.000464850279223623,-0.000464850279653178,0;-0.000422889908523924,-0.000422889907725896,-0.000422890131053791,-0.000422890131057371,-0.000422890131054291,-0.000422890131057855,-0.000422890131054043,-0.000422890131057684,-0.000422890135180004,-0.000422890135893310,0;-0.000348309559422107,-0.000348309558947132,-0.000348309691864400,-0.000348309691866537,-0.000348309691864830,-0.000348309691866954,-0.000348309691864606,-0.000348309691866753,-0.000348309694320250,-0.000348309694744800,43.0436491684950;-0.000317448219995202,-0.000317448219204558,-0.000317448440465745,-0.000317448440469294,-0.000317448440466157,-0.000317448440469703,-0.000317448440465946,-0.000317448440469510,-0.000317448444553722,-0.000317448445260454,71.6525962622234;-0.000231995660577381,-0.000231995660577364,-0.000231995660576710,-0.000231995660576727,-0.000231995660577002,-0.000231995660576996,-0.000231995660576870,-0.000231995660576862,-0.000231995660576844,-0.000231995660576842,-0.00231995647785187;-0.000211826109957630,-0.000211826109957637,-0.000211826109956729,-0.000211826109956725,-0.000211826109957006,-0.000211826109957009,-0.000211826109956874,-0.000211826109956867,-0.000211826109956849,-0.000211826109956848,-0.00211826098201988;-0.000115896358074637,-0.000115896358074632,-0.000115896358074308,-0.000115896358074307,-0.000115896358074440,-0.000115896358074445,-0.000115896358074386,-0.000115896358074375,-0.000115896358074369,-0.000115896358074373,-0.00115896351684206;-0.000106013267225990,-0.000106013267225966,-0.000106013267225503,-0.000106013267225519,-0.000106013267225655,-0.000106013267225648,-0.000106013267225582,-0.000106013267225588,-0.000106013267225578,-0.000106013267225575,-0.00106013261328094];
ubar = [ubar1 ubar2 ubar3];
%% Kalman gain obtaind from solver result
K1 = [44.0635380945976,0.0144792342297621,0.00899088120540256,-0.0124382672869247,-0.0223441170985152,-14.6762348967978,-29.3464412433947,-0.0100789965127368,-0.0183297272704375,-0.00148141843763935,-0.00558644338784057;72.9973128950942,0.0244479819082575,0.0153090895709597,-0.0201779270976766,-0.0365491331966745,-24.3128391828889,-48.6159239970137,-0.0161442327881510,-0.0300272845581608,-0.00200941463662751,-0.00878084663970879;43.5507054837716,0.0144200653254241,0.00898094935076691,-0.0121928816277802,-0.0219638690448114,-14.5053129127818,-29.0047439028058,-0.00984404045116668,-0.0180157931805780,-0.00131719338963689,-0.00536440740900765;72.3219199166351,0.0241936868346877,0.0151660575668501,-0.0200027039117206,-0.0362572464667515,-24.0877901457276,-48.1657843934554,-0.0158107503157870,-0.0295520299572297,-0.00180944623703407,-0.00850184559544692;0,0.0143473042089087,0.00895446326796452,-0.0119783647393111,-0.0216170886824211,-14.3363020536890,-28.6668482923762,-0.00959862061015196,-0.0176755508650136,-0.00120934496620102,-0.00520471650514216;0,0.0240875170155106,0.0151235909454769,-0.0197116546030324,-0.0358156872907119,-23.8645602682563,-47.7198464280140,-0.0155440294572866,-0.0292536758614791,-0.00181252602425768,-0.00843758446433569;0,0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0,0];
K2 = [-0.000581629140520318,-0.000581629140014967,-0.000581629281435421,-0.000581629281437707,-0.000581629281436155,-0.000581629281438415,-0.000581629281435776,-0.000581629281438066,-0.000581629284048542,-0.000581629284500241,33.1028257072545,0,0.0112490119602310,0.0112473556934346,-0.00292777573905732,-0.00436087360384590,-0.00834074815108921,-0.0130520322384191,-11.0275646016738,-22.0540143645686,-0.00657393380603968,-0.0144146452715128;-0.000528160781767472,-0.000528160780932333,-0.000528161014651370,-0.000528161014655111,-0.000528161014652074,-0.000528161014655837,-0.000528161014651727,-0.000528161014655437,-0.000528161018969639,-0.000528161019716197,54.7082630863979,0,0.0189286284954669,0.0189103757597692,-0.00454113156244581,-0.00689384922596755,-0.0135015600147111,-0.0210767833743903,-18.2242737481433,-36.4471019107356,-0.0105525110348784,-0.0235426487928676;-0.000464850137462193,-0.000464850136962711,-0.000464850276737639,-0.000464850276739886,-0.000464850276738278,-0.000464850276740523,-0.000464850276737923,-0.000464850276740185,-0.000464850279320284,-0.000464850279766736,0,32.7179153179613,0.0112345673342110,0.0112163959609964,-0.00278319683941357,-0.00418577411828557,-0.00814214715349870,-0.0128358008736269,-10.8992135703394,-21.7973468908096,-0.00639021248503765,-0.0141171908707592;-0.000422889900322715,-0.000422889899495272,-0.000422890131052072,-0.000422890131055772,-0.000422890131052567,-0.000422890131056314,-0.000422890131052341,-0.000422890131056058,-0.000422890135330305,-0.000422890136069922,0,54.2017664448784,0.0189102797440820,0.0188790780054832,-0.00431688326309377,-0.00666606535534156,-0.0132115671865431,-0.0207785265821466,-18.0555781694114,-36.1098118292599,-0.0103030776224307,-0.0231185845624800;-0.000348309554208820,-0.000348309553715187,-0.000348309691863313,-0.000348309691865506,-0.000348309691863733,-0.000348309691865966,-0.000348309691863537,-0.000348309691865716,-0.000348309694415777,-0.000348309694857077,32.3368807977701,0,0.0112181867735355,0.0112050146547400,-0.00264624138886693,-0.00403942571585900,-0.00793936627616469,-0.0125083755937647,-10.7721706065646,-21.5434283256527,-0.00620675334625093,-0.0138480011120754;-0.000317448211869598,-0.000317448211049784,-0.000317448440464021,-0.000317448440467722,-0.000317448440464449,-0.000317448440468131,-0.000317448440464258,-0.000317448440467932,-0.000317448444702636,-0.000317448445435430,53.7005126816206,0,0.0188306154290914,0.0187983500141845,-0.00418479906990456,-0.00650422788317405,-0.0129787758516639,-0.0206037169145362,-17.8884600942730,-35.7756277679274,-0.0100996300998782,-0.0228571188161968;-0.000231995524496290,-0.000231995524008378,-0.000231995660548183,-0.000231995660550392,-0.000231995660548475,-0.000231995660550666,-0.000231995660548338,-0.000231995660550513,-0.000231995663070879,-0.000231995663507021,31.9604088939063,0,0.0112066324330570,0.0112147539670611,-0.00249739118314646,-0.00392555353680225,-0.00771411199815516,-0.0122641592061716,-10.6466425028912,-21.2924601288557,-0.00600142224565183,-0.0136449665955420;-0.000211825883430054,-0.000211825882617863,-0.000211826109909245,-0.000211826109912894,-0.000211826109909523,-0.000211826109913165,-0.000211826109909373,-0.000211826109913023,-0.000211826114108563,-0.000211826114834567,53.2033600166952,0,0.0188448086146954,0.0187787624459470,-0.00397036507284986,-0.00630757558107225,-0.0127006896994598,-0.0202050826654821,-17.7227112959222,-35.4443641534376,-0.00985352249305821,-0.0229891634134136;-0.000115896358074734,-0.000115896358074724,-0.000115896358074296,-0.000115896358074303,-0.000115896358074448,-0.000115896358074456,-0.000115896358074386,-0.000115896358074361,-0.000115896358074363,-0.000115896358074379,-0.00115896351690545,0,0,0,0,0,0,0,0,0,0,0;-0.000106013267226122,-0.000106013267226104,-0.000106013267225503,-0.000106013267225519,-0.000106013267225655,-0.000106013267225651,-0.000106013267225582,-0.000106013267225583,-0.000106013267225577,-0.000106013267225575,0,-0.00106013261346298,0,0,0,0,0,0,0,0,0,0];
K3 = [-0.000581629135519974,-0.000581629134996698,-0.000581629281434357,-0.000581629281436717,-0.000581629281435096,-0.000581629281437487,-0.000581629281434781,-0.000581629281437079,-0.000581629284140153,-0.000581629284607911,26.5256579509458,0,0.00835038284765902,0.00947832280545638,-0.000533997427724830,-6.68585671312291e-06,-0.00405488169836614,-0.00564807655900998,-0.00595031101092397,-0.0109888523403815,-8.84050296644894,-17.6817277853915;-0.000528160774083449,-0.000528160773220748,-0.000528161014649796,-0.000528161014653655,-0.000528161014650437,-0.000528161014654326,-0.000528161014650111,-0.000528161014653958,-0.000528161019110479,-0.000528161019881656,0,43.7323827136632,0.0140321836641676,0.0159035734195373,-0.000542426950676478,0.000364240646642466,-0.00625922274696526,-0.00888142880463039,-0.00945508644359899,-0.0175429498368847,-14.5745638190296,-29.1508198297976;-0.000464850132519463,-0.000464850132002244,-0.000464850276736625,-0.000464850276738974,-0.000464850276737208,-0.000464850276739529,-0.000464850276736892,-0.000464850276739237,-0.000464850279410886,-0.000464850279873170,0,26.2170978854204,0.00839666410543007,0.00946862846858551,-0.000444547095147061,8.91388874535797e-05,-0.00392615549751531,-0.00547020218953360,-0.00581631085589865,-0.0107350123263100,-8.73755516972260,-17.4757534214187;-0.000422889892709482,-0.000422889891854738,-0.000422890131050451,-0.000422890131054295,-0.000422890131050992,-0.000422890131054839,-0.000422890131050725,-0.000422890131054571,-0.000422890135469843,-0.000422890136233858,43.3276919263775,0,0.0140211697873117,0.0160142083983239,-0.000366651051102402,0.000478818303015614,-0.00607735037249898,-0.00860533574328808,-0.00911470174798128,-0.0173708258234057,-14.4396727514416,-28.8812274072871;-0.000348309549323091,-0.000348309548811909,-0.000348309691862276,-0.000348309691864573,-0.000348309691862713,-0.000348309691865016,-0.000348309691862500,-0.000348309691864786,-0.000348309694505334,-0.000348309694962264,0,25.9122873075480,0.00837341318636336,0.00954768611622805,-0.000271138675591953,0.000155350652316167,-0.00376835543820737,-0.00533741699325959,-0.00563027057910208,-0.0105847090624864,-8.63581190567657,-17.2724430575202;-0.000317448204326399,-0.000317448203479583,-0.000317448440462472,-0.000317448440466267,-0.000317448440462869,-0.000317448440466661,-0.000317448440462651,-0.000317448440466486,-0.000317448444840901,-0.000317448445597841,0,42.9271217709031,0.0140008448155133,0.0158117464386425,-0.000281578836956038,0.000561272672078999,-0.00608381201958536,-0.00834542194250592,-0.00891479934815123,-0.0171139707435029,-14.3061071810531,-28.6138233546433;-0.000231995519666879,-0.000231995519161643,-0.000231995660547176,-0.000231995660549459,-0.000231995660547456,-0.000231995660549719,-0.000231995660547326,-0.000231995660549600,-0.000231995663159393,-0.000231995663610998,0,25.6105655006555,0.00825393995232175,0.00935996007256233,-0.000324169279509413,0.000194898147037028,-0.00372020476659378,-0.00501585548608801,-0.00530996212076040,-0.0101735252828744,-8.53504170390693,-17.0711088341814;-0.000211825875956376,-0.000211825875117378,-0.000211826109907680,-0.000211826109911447,-0.000211826109907945,-0.000211826109911717,-0.000211826109907806,-0.000211826109911582,-0.000211826114245537,-0.000211826114995488,42.5305249978802,0,0.0140376983366531,0.0159144637481751,-0.000164166896230518,0.000626851134912908,-0.00600537149991451,-0.00843348581306537,-0.00900589897935376,-0.0169609079999982,-14.1736314302266,-28.3490210102000;-0.000115896218804857,-0.000115896218305517,-0.000115896358045113,-0.000115896358047351,-0.000115896358045253,-0.000115896358047496,-0.000115896358045170,-0.000115896358047424,-0.000115896360626858,-0.000115896361073200,0,25.3125511016011,0.00836257814113481,0.00941757713773058,-0.000126986021959314,0.000379968576672813,-0.00350929619294082,-0.00494546128359014,-0.00522984039418426,-0.0100579904300554,-8.43566564435439,-16.8723349700185;-0.000106013035390354,-0.000106013034559113,-0.000106013267176911,-0.000106013267180650,-0.000106013267177042,-0.000106013267180788,-0.000106013267176985,-0.000106013267180711,-0.000106013271474569,-0.000106013272217585,0,42.1367074550257,0.0140593145017628,0.0158875194539718,-6.90156975402793e-05,0.000796806145614419,-0.00560810907779284,-0.00825150493231501,-0.00872792090512335,-0.0167696079526953,-14.0424571232569,-28.0866279454555];
%K = [K1 K2 K3];
K = [44.0635380945976,0.0144792342297621,0.00899088120540256,-0.0124382672869247,-0.0223441170985152,-14.6762348967978,-29.3464412433947,-0.0100789965127368,-0.0183297272704375,-0.00148141843763935;72.9973128950942,0.0244479819082575,0.0153090895709597,-0.0201779270976766,-0.0365491331966745,-24.3128391828889,-48.6159239970137,-0.0161442327881510,-0.0300272845581608,-0.00200941463662751;43.5507054837716,0.0144200653254241,0.00898094935076691,-0.0121928816277802,-0.0219638690448114,-14.5053129127818,-29.0047439028058,-0.00984404045116668,-0.0180157931805780,-0.00131719338963689;72.3219199166351,0.0241936868346877,0.0151660575668501,-0.0200027039117206,-0.0362572464667515,-24.0877901457276,-48.1657843934554,-0.0158107503157870,-0.0295520299572297,-0.00180944623703407;0,0.0143473042089087,0.00895446326796452,-0.0119783647393111,-0.0216170886824211,-14.3363020536890,-28.6668482923762,-0.00959862061015196,-0.0176755508650136,-0.00120934496620102;0,0.0240875170155106,0.0151235909454769,-0.0197116546030324,-0.0358156872907119,-23.8645602682563,-47.7198464280140,-0.0155440294572866,-0.0292536758614791,-0.00181252602425768;0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0;0,0,0,0,0,0,0,0,0,0];

%% Constructing mean of state
xbar0 = ones(2,55);
xbar = (Gxx*xbar0)+(Gxu*ubar);
%% Main loop
x0 = ones(2,55);
x(:,1) = ones(10,55);
for k = 2:55
    x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);
end
plot(x)

[Stephen23]

Given that x is not defined previously, what do you expect this line to do?:

x(:,1) = ones(10,55);

Possibly you meant to write this (but your allocation error indicates that there might be deeper confusion...):

x = ones(10,55);

When I display the size of the calculation results like this

for k = 2:55
    tmp = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);
    size(tmp) % show size of results
end

this is what it shows me:

ans =
   10   55
ans =
   10   55
ans =
   10   55
ans =
   10   55
ans =
   10   55
... lots more times the same
ans =
   10   55
ans =
   10   55
ans =
   10   55
ans =
   10   55
ans =
   10   55

In your code you try to allocate these results to x using:

   x(:,k) = ...

which refers to exactly 10 elements. How do you expect to fit 550 elements into 10 elements?

[Ali Esmaeilpour]

so how to pre-allocate correctly in order to have a true answer? when I say x(:,1) = ones(10,55) I mean for k=1 x is this. maybe this one:

%% Main loop
x0 = ones(2,55);
%u = K*(x-xbar)+ubar;
x = ones(10,55);
for k = 2:55
    x(:,1) = ones(10,55);
    x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);
end
plot(x)

[Ali Esmaeilpour]

but it still says:

Unable to perform assignment because the size of the left side is 10-by-1 and the size of the right side is 10-by-55.

Error in Untitled2 (line 62)

x(:,1) = ones(10,55);

[Ali Esmaeilpour]

removed that and I got:

Unable to perform assignment because the size of the left side is 10-by-1 and

the size of the right side is 10-by-55.

Error in Untitled2 (line 63)

x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);

[madhan ravi]

what is the purpose of x(:.1) =... ?

[Ali Esmaeilpour]

well I don't know lol, but when I remove that and use k=1:10:

%% Main loop
x0 = ones(2,55);
%u = K*(x-xbar)+ubar;
x = ones(10,55);
for k = 1:10
    x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);
end
plot(x)

and I got:

Index in position 2 is invalid. Array indices must be positive integers or

logical values.

Error in Untitled2 (line 62)

x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);

[madhan ravi]

MATLAB doesn’t allow zero indexing k-1 leads to zero when k is 1

[Ali Esmaeilpour]

so that's the usage of x(:,1). k=2:10 and k-1=1 when k=2

[Ali Esmaeilpour]

I don't know how to debug this:

%% Main loop
x0 = ones(2,55);
%u = K*(x-xbar)+ubar;
x = ones(10,55);
for k = 2:10
    x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);
end
plot(x)

error is:

Unable to perform assignment because the size of the left side is 10-by-1 and

the size of the right side is 10-by-55.

Error in Untitled2 (line 62)

x(:,k) = Gxx*x0 + Gxu*(K*(x(:,k-1)-xbar)+ubar);

[Stephen23]

You can preallocate a correctly sized array and use suitable indexing, e.g.:

x = ones(10,55,10);
for k = 2:10
    x(:,:,k) = ...
end

[Ali Esmaeilpour]

how about this:

%% Main loop
x0 = ones(2,55);
x = ones(10,55);
for k = 2:55
    x(:,:) = (Gxx*x0)+(Gxu*(K*(x(:,k-1)-xbar))+(ubar));
end

working fine!

[Stephen23]

"working fine!"

Sure... except that you replace the entire contents of array x on every iteration, thus discarding the results from every iteration except the last one. I doubt that that is what you are after.

[Guillaume]

Stephen has already shown you how to allocate enough elements as a 3D array. It's very simple, if you're going to generate 5500 numbers, you need an array with 5500 elements, not 550. How you allocate that is up to you, as a 3D array as Stephen showed, as a 10x550 2D array, as a 100x55 array, etc. but you need 5500 elements.

Note that x(:, :) = ... when x is 2D is exactly the same as x = .... The indexing does nothing useful and just shows that you're confused.

[Ali Esmaeilpour]

I can't get what you try to tell me. question is clear x is 10*55 and it has a formula:

x = (Gxx*x0)+(Gxu*(K*(x-xbar))+(ubar))

I want to find it through a for loop and it's 2D not 3D

I already told you the way I tried and it's failed so help me plz

[Stephen23]

"question is clear x is 10*55 and it has a formula:"

Sure, that much is clear.

But what is not clear is what you expect to be stored in the output array, because

a) your code is buggy, so it does not help us understand what you are trying to do, and

b) you have not explained the output array to us, even though this thread of >ten comments discusses this one topic extensively.

So, here is an important question for you: Given that on each of ten iterations you generate a matrix with size 10x55, and you apparently want them all stored, what size do you expect the final output array to be? Please answer this exact question.

Note that ten iterations of a 10x55 matrix means a total of 5500 elements.

[Ali Esmaeilpour]

ok, eh... I did an optimization through a solver and I got K and ubar (mean of input) as a controller. then I found xbar (mean of states) through its formula. then I wanna put u and K in a close loop through for command and find x (states) and input (u). I attach x and u formula and also xbar maybe it could help you to know what am I doing exactly. and w is random numbers with normal destribution which means w=randn(10,55)