MATLAB: How to fix “unrecognized variable error”-

quick fix solutionssomebody helpmetruss optimization

%Hi team please I'm stuck :(. Whenever I run the program "truss2D_optimization", it shows me error at truss2D_nlcon.m file saying
"Unrecognized function or variable 'ifdoflimit'.
Error in truss2D_nlcon (line 154)
if ifdoflimit(idof)==11
Error in truss2D_optimization (line 34)
[C,Ceq] = truss2D_nlcon(coorddofvar0);
"
TITLE = buckling_check_1
ELEMENTS = 9
1 1 2 1.53e-4 0.68e-8
2 2 3 1.53e-4 0.68e-8
3 1 3 1.53e-4 0.68e-8
4 1 4 1.53e-4 0.68e-8
5 3 4 1.53e-4 0.68e-8
6 3 6 1.53e-4 0.68e-8
7 3 5 1.53e-4 0.68e-8
8 4 5 1.53e-4 0.68e-8
9 6 5 1.53e-4 0.68e-8
NODE_COORDINATES = 6
1 0.0 0.0
2 0.0 4.0
3 5.0 4.0
4 5.0 0.0
5 10.0 0.0
6 10.0 4.0
NODES_WITH_PRESCRIBED_DISPLACEMENTS = 2
1 11 0.000 0.000
5 11 0.000 0.000
YOUNG_MODULUS =210000.0
YIELD STRESS =250.0
NODES_WITH_POINT_LOAD = 3
2 0 -100
4 0 -50
6 0 -100
PLOTTING_AMPLIFICATION_FACTOR = 10
NODES_WITH_VARIABLE_COORDINATES = 4
2 01 0.1 0.1 1.0 1.5
3 01 0.1 0.1 1.0 1.5
4 01 0.1 0.1 1.0 1.5
6 01 0.1 0.1 1.0 1.5
DEFLECTION_LIMIT = 4
2 11 0.01 0.05
3 11 0.01 0.05
4 11 0.01 0.05
6 11 0.01 0.05
%The end of the text file. The next .m file (truss2D_readdata) will read the info in the txt file
%truss2D_readdata
%**********************************************************************

% Reads all data for a 2D linear elastic truss
%

% HISTORY

% October 2018, : Initial coding (from "truss2D.m")
%***********************************************************************

function [coorddofvar,fixeddata] = truss2D_readdata(filename)
%
% Set some basic variables
% ========================
% Number of degrees of freedom per node
ndofn=2;
% Number of nodes of the element
nnode=2;
%
% Read information from data file
% ===============================
%
fid = fopen(filename, 'r');
title = fscanf(fid, 'TITLE = %s',1);
%
% Total number of elements in the mesh
nelem = fscanf(fid, '\nELEMENTS = %d', 1);
%
%Read Table of connectivities
%
lnods = fscanf(fid, '\n%d %d %d %f %f', [nnode+3,nelem]);
lnods = lnods';sortrows(lnods,1);
%...cross-sectional areas
csarea = lnods(:,4);
%...second moment of areas
sndmoa = lnods(:,5);
%...store only connectivities in lnods
lnods = lnods(:,2:nnode+1);
%...create table of element global degrees of freedom
eldofX = lnods*ndofn-1; eldofY = lnods*ndofn;
eldofs = [ eldofX(:,1) eldofY(:,1) eldofX(:,2) eldofY(:,2) ];
%
% Read Nodal coordinates
%
npoin = fscanf(fid, '\nNODE_COORDINATES = %d', 1);
coord = fscanf(fid, '\n%d %f %f', [3, npoin]);
coord = coord';sortrows(coord,1);nodnumbers=coord(:,1);
coord = coord(:,2:3);
%...create table of nodal degrees of freedom
nodofs = [ nodnumbers*ndofn-1 nodnumbers*ndofn ];
%
%
% Read Prescribed displacements
%
nnodefix = fscanf(fid,'\nNODES_WITH_PRESCRIBED_DISPLACEMENTS = %d',1);
ipresc = fscanf(fid, '\n%d %d %f %f', [2+ndofn, nnodefix]);
ipresc = ipresc';fixednodes=ipresc(:,1);
%...create tables of fixed dofs and corresponding prescribed values

ifdoffix = zeros(npoin*ndofn,1); icount = 0;
for inodefix = 1:nnodefix
ipoin=ipresc(inodefix,1);
dofX=nodofs(ipoin,1);dofY=nodofs(ipoin,2);
if ipresc(inodefix,2)==11
ifdoffix(dofX)=1;
ifdoffix(dofY)=1;
icount = icount+1;
valuedoffix(icount) = ipresc(inodefix,3);
fixeddoftable(icount) = dofX;
icount = icount+1;
valuedoffix(icount) = ipresc(inodefix,4);
fixeddoftable(icount) = dofY;
elseif ipresc(inodefix,2)==1
ifdoffix(dofY)=1;
icount = icount+1;
valuedoffix(icount) = ipresc(inodefix,4);
fixeddoftable(icount) = dofY;
elseif ipresc(inodefix,2)==10
ifdoffix(dofX)=1;
icount = icount+1;
valuedoffix(icount) = ipresc(inodefix,3);
fixeddoftable(icount) = dofX;
elseif ipresc(inodefix,2)==0
else
error('Wrong displacement prescription code in data file')
end
end
%...create table of free dofs by subtracting the set of fixed dofs
% from the set of all dofs
ngdof=npoin*ndofn;alldoftable=[1:ngdof]';
freedoftable = setxor(alldoftable,fixeddoftable);
%
% Read Material properties
%
matprop.young = fscanf(fid, '\nYOUNG_MODULUS = %f', 1);
matprop.yield = fscanf(fid, '\nYIELD STRESS = %f', 1);
%
%Read Load vector (point loads only)
%
npload = fscanf(fid,'\nNODES_WITH_POINT_LOAD = %d',1);
pload = fscanf(fid, '\n%d %f %f', [1+ndofn, npload]);
pload = pload';
%...add point loads to global load vector
F=zeros(ngdof,1);
loadednodes=pload(:,1);
loadeddofs=nodofs(loadednodes,:);
F(loadeddofs) = pload(:,2:3);
%
% Reads deformation amplification factor (for plotting only)
amplfact = fscanf(fid,'\nPLOTTING_AMPLIFICATION_FACTOR = %d',1);
%
% Reads upper and lower bounds of variable coordinates to be optimised
%
nnodevar = fscanf(fid, '\nNODES_WITH_VARIABLE_COORDINATES = %d', 1);
ivar = fscanf(fid, '\n%d %d %f %f %f %f', [2+2*ndofn, nnodevar]);
ivar = ivar';varnodes=ivar(:,1);
%...create tables of variable coordinates and corresponding prescribed
% upper and lower bounds
ifcoordvar = zeros(npoin*ndofn,1); icount = 0;
upperbound=[];lowerbound=[];dofcoordvar=[];
for inodevar = 1:nnodevar
ipoin=ivar(inodevar,1);
dofX=nodofs(ipoin,1);dofY=nodofs(ipoin,2);
if ivar(inodevar,2)==11
% both x- and y-coordinates are variable
ifcoordvar(dofX)=1;
ifcoordvar(dofY)=1;
icount = icount+1;
lowerbound(icount) = ivar(inodevar,3);
upperbound(icount) = ivar(inodevar,5);
dofcoordvar(icount) = dofX;
icount = icount+1;
lowerbound(icount) = ivar(inodevar,4);
upperbound(icount) = ivar(inodevar,6);
dofcoordvar(icount) = dofY;
elseif ivar(inodevar,2)==1
% only y-coordinate is variable
ifcoordvar(dofY)=1;
icount = icount+1;
lowerbound(icount) = ivar(inodevar,4);
upperbound(icount) = ivar(inodevar,6);
dofcoordvar(icount) = dofY;
elseif ivar(inodevar,2)==10
% only x-coordinate is variable
ifcoordvar(dofX)=1;
icount = icount+1;
lowerbound(icount) = ivar(inodevar,3);
upperbound(icount) = ivar(inodevar,5);
dofcoordvar(icount) = dofX;
elseif ivar(inodevar,2)==0
disp('WARNING: Node listed with no variable coordinates for optimisation process')
else
error('Wrong variable coordinate prescription code in data file')
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% APPENDED CODE STARTS FROM HERE
%Read deflection limit from data file
nnodelimit = fscanf(fid,'\nDEFLECTION_LIMIT = %d',1);
ilimit = fscanf(fid, '\n%d %d %f %f', [2+ndofn, nnodelimit]);
ilimit = ilimit';limitednodes=ilimit(:,1);
%...create tables of fixed dofs and corresponding prescribed values
ifdoflimit = zeros(npoin*ndofn,1); iicount = 0;
for inodelimit = 1:nnodelimit
ipoin=ilimit(inodelimit,1);
dofX=nodofs(ipoin,1);
dofY=nodofs(ipoin,2);
if ilimit(inodelimit,2)==11
ifdoflimit(dofX)=1;
ifdoflimit(dofY)=1;
iicount = iicount+1;
valuedoflimit(iicount)= ilimit(inodelimit,3);
limiteddoftable(iicount) = dofX;
iicount = iicount+1;
valuedoflimit(iicount) = ilimit(inodelimit,4);
limiteddoftable(iicount)= dofY;
elseif ilimit(inodelimit,2)==1
ifdoflimit(dofY)=1;
iicount = iicount+1;
valuedoflimit(iicount)= ilimit(inodelimit,4);
limiteddoftable(iicount) = dofY;
elseif ilimit(inodefix,2)==10
ifdoflimit(dofX)=1;
iicount = iicount+1;
valuedoflimit(iicount) = ilimit(inodelimit,3);
limiteddoftable(iicount) = dofX;
elseif ilimit(inodelimit,2)==0
else error('Deflection limitaion value is not inserted')
end
end
%************************************************************************

%
% IMPORTANT
% (DEFINIFION OF DESIGN VARIABLES)
%
% set of dofs associated with variable coordinates
dofcoordfix=setxor(alldoftable,dofcoordvar);
if isempty(dofcoordvar)
disp('No variables in optimisation problem - all nodes have fixed coordinates')
error('No variables in optimisation problem - all nodes have fixed coordinates')
end
%
% arrange coordinates following dof ordering (in one-dimensional array, as
% in global displacement vector)
coorddof=zeros(ngdof,1);
for ipoin=1:npoin
dofx=ipoin*2-1;dofy=ipoin*2;
coorddof(dofx)=coord(ipoin,1);coorddof(dofy)=coord(ipoin,2);
end
% split coordinates array into variable and fixed coordinates
coorddofvar=coorddof(dofcoordvar);coorddoffix=coorddof(dofcoordfix);
%AppRita
coorddoflimit=coorddof(alldoftable);
%x = coorddofvar
%************************************************************************
%
% Store fixed data in structure
fixeddata.amplfact=amplfact;
fixeddata.coorddoffix=coorddoffix;
fixeddata.csarea=csarea;
fixeddata.sndmoa=sndmoa;
fixeddata.dofcoordfix=dofcoordfix;
fixeddata.dofcoordvar=dofcoordvar;
fixeddata.eldofs=eldofs;
fixeddata.F=F;
fixeddata.fixeddoftable=fixeddoftable;
fixeddata.freedoftable=freedoftable;
fixeddata.lnods=lnods;
fixeddata.lowerbound=lowerbound;
fixeddata.matprop=matprop;
fixeddata.ndofn=ndofn;
fixeddata.nelem=nelem;
fixeddata.ngdof=ngdof;
fixeddata.npoin=npoin;
fixeddata.upperbound=upperbound;
fixeddata.valuedoffix=valuedoffix;
%fixeddata.coorddoflimit=coorddoflimit; %appended by
%fixeddata.coorddoflimit=coorddoflimit;
fixeddata.limiteddoftable=limiteddoftable;
fixeddata.valuedoflimit=valuedoflimit;
fixeddata.csarea=csarea;
fixeddata.sndmoa=sndmoa;
% Close file(s)
status = fclose(fid);
%
end
%The end of the M file. The next .m file (truss2D_nlcon) will read the info in the truss2D_nlcon
%truss2D_nlcon
%**********************************************************************
% Constraint function for optimization of linear elastic 2D trusses
%
% HISTORY
% October 2018, Initial coding
%***********************************************************************
function [C,Ceq] = truss2D_nlcon(coorddofvar)
%
global fixeddata
global R
global U
%
% Retrieve fixed data from structure
coorddoffix=fixeddata.coorddoffix;
csarea=fixeddata.csarea;
dofcoordfix=fixeddata.dofcoordfix;
dofcoordvar=fixeddata.dofcoordvar;
eldofs=fixeddata.eldofs;
F=fixeddata.F;
fixeddoftable=fixeddata.fixeddoftable;
freedoftable=fixeddata.freedoftable;
lnods=fixeddata.lnods;
matprop=fixeddata.matprop;
ndofn=fixeddata.ndofn;
nelem=fixeddata.nelem;
ngdof=fixeddata.ngdof;
npoin=fixeddata.npoin;
valuedoffix=fixeddata.valuedoffix;
sndmoa=fixeddata.sndmoa;
%fixeddata.coorddoflimit=coorddoflimit; %appended by Rita
limiteddoftable=fixeddata.limiteddoftable;
valuedoflimit=fixeddata.valuedoflimit;
%coorddofvar=fixeddata.coorddofvar;
%
% arrange coordinates in usual 2-dimensional array format (node by node)

coorddof(dofcoordfix)=coorddoffix;coorddof(dofcoordvar)=coorddofvar;
%...compute elements length and angle sine/cosine

elength=zeros(nelem,1);
for ielem=1:nelem
elvec=coorddof(eldofs(ielem,3:4))-coorddof(eldofs(ielem,1:2));
elength(ielem)=sqrt(elvec*elvec');
end
% arrange coordinates in usual 2-dimensional array format (node by node)
coorddof(dofcoordfix)=coorddoffix;coorddof(dofcoordvar)=coorddofvar;
% coord=zeros(npoin,2);
% for ipoin=1:npoin
% dofx=ipoin*2-1;dofy=ipoin*2;
% coord(ipoin,1)=coorddof(dofx);coord(ipoin,2)=coorddof(dofy);
% end
%...compute elements length and angle sine/cosine
elength=zeros(nelem,1);e

Best Answer

Rita - the error message
"Unrecognized function or variable 'ifdoflimit'.
Error in truss2D_nlcon (line 154)
if ifdoflimit(idof)==11
Error in truss2D_optimization (line 34)
[C,Ceq] = truss2D_nlcon(coorddofvar0);
is valid since the truss2D_optimization function is trying to use the variable ifdoflimit which is only created (but not returned from) truss2D_readdata. If ifdoflimit is truly needed in the optimization function, then I recommend that you change the truss2D_readdata signature to return this parameter.