How can I get rid of this error? Please help me guys

Question

Nahid 2015-4-10

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/197118-how-can-i-get-rid-of-this-error-please-help-me-guys

移动：DGM 2023-2-24

E = 10e7; poisson = 0.30;
C=E/(1-poisson^2)*[1 poisson 0;poisson 1 0;0 0 (1-poisson)/2];
P = 1e6;
Lx=5; Ly=1;
numberElementsX=20;
numberElementsY=10;
numberElements=numberElementsX*numberElementsY;
[nodeCoordinates, elementNodes] =rectangularMesh(Lx,Ly,numberElementsX,numberElementsY);
xx=nodeCoordinates(:,1);
yy=nodeCoordinates(:,2);
drawingMesh(nodeCoordinates,elementNodes,'Q4','k-');
numberNodes=size(xx,1);
GDof=2*numberNodes;
stiffness=formStiffness2D(GDof,numberElements,elementNodes,numberNodes,nodeCoordinates,C,1,1); % boundary conditions
fixedNodeX=find(nodeCoordinates(:,1)==0);
fixedNodeY=find(nodeCoordinates(:,1)==0); % fixed in YY
prescribedDof=[fixedNodeX; fixedNodeY+numberNodes];
force=zeros(GDof,1);
rightBord=find(nodeCoordinates(:,1)==Lx);
force(rightBord+numberNodes)=P*Ly/numberElementsY;
force(rightBord(1)+numberNodes)=P*Ly/numberElementsY/2;
force(rightBord(end)+numberNodes)=P*Ly/numberElementsY/2;
displacements=solution(GDof,prescribedDof,stiffness,force);
% displacements and deformed shape
disp('Displacements')
jj=1:GDof; format f=[jj; displacements'];
fprintf('node U\n') fprintf('%3d %12.8f\n',f)
UX=displacements(1:numberNodes); UY=displacements(numberNodes+1:GDof);
scaleFactor=0.1; figure
drawingField(nodeCoordinates+scaleFactor*[UX UY],elementNodes,'Q4',UX);%U XX hold on
drawingMesh(nodeCoordinates+scaleFactor*[UX UY],elementNodes,'Q4','k-');
drawingMesh(nodeCoordinates,elementNodes,'Q4','k--');
colorbar
title('U XX (on deformed shape)')
axis off
% stresses at nodes stresses2D(GDof,numberElements,elementNodes,numberNodes,nodeCoordinates,displacements,UX,UY,C,scaleFactor);

''Undefined function or variable "nodeCoordinates".''

[nodeCoordinates, elementNodes] =rectangularMesh(Lx,Ly,numberElementsX,numberElementsY);

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ni 2023-2-24

Dear friend，I want to know how this drawingmesh function is implemented

Walter Roberson 2023-2-24

@ni

It has a switch on the requested element type, and calls plot3() or patch() as appropriate.

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Answer 1

John D'Errico 2015-4-10

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/197118-how-can-i-get-rid-of-this-error-please-help-me-guys#answer_174696

在 MATLAB Online 中打开

READ THE ERROR MESSAGE.

So where in this script have you defined the variable nodeCoordinatea?

It was generated by rectangularMesh, a code that is NOT supplied by MathWorks. Try this:

which rectangularMesh -all

Do you have that function? If not, then you will need to download it, as well as its companions from this site:

http://extras.springer.com/2009/978-1-4020-9199-5/MATLABsoftware

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loukmane el khaldi 2019-5-14

I downloaded the files and I tried to execute this file: rectangular Mesh.p but this message appears "Warning: The P-code file MATLABsoftware_rectangularMesh.p was generated prior to MATLAB version 7.5 (R2007b) and will Use MATLABsoftware_rectangularMesh.p using MATLAB R2007b or later. " How do I correct this error? Help me please.

Walter Roberson 2019-5-14

You can hope that nothing bad happens, but if it fails then you would have to go back go Springer to ask them to update the file, which they would pass along to the author of the book. However I would tend to doubt there would be any actual result.

Alternately if you do not have a Student license (not sure about a Home license) then you can probably use your existing license to access MATLAB R2007a and run the code with that.

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Answer 2

waqas 2019-8-26

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/197118-how-can-i-get-rid-of-this-error-please-help-me-guys#answer_389031

在 MATLAB Online 中打开

You can use following rectangularMesh function to generate the same parameters. I hope this works for your code.

function [nodeCoordinates,elementNodes] = rectangularMesh(Lx,Ly,...
                                         numberElementsX,numberElementsY)
              xx = 0:Lx/numberElementsX:Lx;
              yy = 0:Ly/numberElementsY:Ly;
              [XX YY] = meshgrid(yy,xx);
              nodeCoordinates = [YY(:),XX(:)];
              elementNodes = zeros(numberElementsX*numberElementsY,4);
              j = 1;
              i =1;
              i1 =0;
              counter = 0;
              for j = 1:numberElementsY
                  for i =1: numberElementsX
                      counter = counter +1;
                      if i ==1 && j==1
                          i1 =1;
                      else
                          i1 = i1 +1;
                      end     
                      
                      i2 = i1 + 1;
                      i4 = i1 + numberElementsX + 1;
                      i3 = i2 + numberElementsX + 1;
                      elementNodes(counter,:) = [i1 i2 i3 i4];
                  end
                   i1 = i1+1;i2 = i2+1;
              end          
 end