Dot indexing is not supported for variables of this type.

I got this error : Dot indexing is not supported for variables of this type.

I will show you the line of code where its happening:

        function [equations] = analyserNoeud(this, indiceNoeud, equations)
     
            forcesExternesX = [];
            forcesExternesY = [];
            forceAppuisX    = [];
            forceAppuisY    = [];
            forcesNoeud     = [];
            normeX = 0;
            normeY = 0;

            
            noeudCourant = this.getNoeud(indiceNoeud);

            
            indiceNoeudConnecte = this.getConnectionIemeNoeud(indiceNoeud);
            for i = 1:size(indiceNoeudConnecte, 2)

                
                indiceVoisin = indiceNoeudConnecte(i);
                voisin =  this.getNoeud(indiceVoisin);

               
                forceCourante = Force(noeudCourant, voisin);
                forcesNoeud = [forcesNoeud, forceCourante];
            end

        %%%%%%This part that make the error Dot indexing is not supported for variables of this type.
%%%%Error in Treillis/analyserNoeud (line 214)
%%%                       this.getForcesReactionsIemeNoeud(indiceNoeud).getForceX(), ...
                           
            forcesX = [forcesNoeud.getForceX(),...
                       this.getForcesReactionsIemeNoeud(indiceNoeud).getForceX(), ...
                       this.getForcesExternesIemeNoeud(indiceNoeud).getForceX()];

            forcesY = [forcesNoeud.getForceY(),...
                       this.getForcesReactionsIemeNoeud(indiceNoeud).getForceY(), ...
                       this.getForcesExternesIemeNoeud(indiceNoeud).getForceY()];

      
            [inconnuesX, equationX, resultante1] = forcesX.somme();

     
            [inconnuesY, equationY, resultante2] = forcesY.somme();

           
            equations.ajouterEquation(inconnuesX, equationX, ...
                                      -resultante1.getComposanteX());
            equations.ajouterEquation(inconnuesY, equationY, ...
                                      -resultante2.getComposanteY());

        end

and also this one

         for i = 1: this.getNbNoeud()
                [equations] = this.analyserNoeud(i, equations);  %this line make the error
            end
        end
        
        
        function [equations] = analyserNoeud(this, indiceNoeud, equations)

You could check the entire program in attachment.

[Geoff Hayes]

Charles-Antoine - I think that you need to post the full error message for each of your two cases where there are errors. Also, it is a little challenging trying to run and step through your code without knowing what the inputs are and (probably) missing code for some of the calls within this class. For example, you say

 [equations] = this.analyserNoeud(i, equations);  %this line make the error

but is it really that line that generates the error or is there an error somewhere in analyserNoeud?

[Charles-Antoine Danis]

[Charles-Antoine Danis]

if you need all the program i could sent it to you.

Answer 1

[Geoff Hayes]

Charles-Antoine - it seems that it is the same line that is causing the problem

this.getForcesReactionsIemeNoeud(indiceNoeud).getForceX(), ...

so what I would do is to put a breakpoint at the line

forcesX = [forcesNoeud.getForceX(),...
                       this.getForcesReactionsIemeNoeud(indiceNoeud).getForceX(), ...
                       this.getForcesExternesIemeNoeud(indiceNoeud).getForceX()];

and then run your app. When the debugger pauses at this line, evaluate (in the command window since in debug "mode")

this.getForcesReactionsIemeNoeud(indiceNoeud)

Did this evaluate successfully or did it generate the error? If the error, then there is something incorrect about your assumptions concerning the this object. If there is no error, then what is

this.getForcesReactionsIemeNoeud(indiceNoeud)

? Is it a struct or an object? If neither of those things then it could be that the problem/error is with the getForcesReactionsIemeNoeud method. If you look closely at the method

        function [forceReactionIemeNoeud] = getForcesReactionsIemeNoeud(this,indiceNoeud)
            Constantes;
            forceReactionIemeNoeud = [];
            typeAppui = this.noeuds(indiceNoeud).getTypeAppui();    
            if (typeAppui == SANS_APPUI)
                Force.empty(1,0);
            else
                forceReactionY = Force();
                nomForceY = sprintf('Fr%gy',indiceNoeud);
                forceReactionY.setNom(nomForceY);
                position = getPosition(this.noeuds(indiceNoeud));
                forceReactionY.setPointAction(position);
                forceReactionY.setOrientation(pi/2);
                forceReactionIemeNoeud = [forceReactionIemeNoeud,forceReactionY]; 
                if(typeAppui == GOUPILLE || typeAppui == ENCASTREMENT)
                    forceReactionX = Force();
                    nomForceX = sprintf('Fr%gx',indiceNoeud);
                    forceReactionX.setNom(nomForceX);
                    forceReactionX.setOrientation(0);
                    forceReactionX.setPointAction(position);
                    forceReactionIemeNoeud = [forceReactionX,forceReactionIemeNoeud];   
                elseif(typeAppui == ENCASTREMENT)
                    momentReaction = Force();
                    nomMoment = sprintf('Fr%gm',indiceNoeud);
                    momentReaction.setNom(nomMoment);
                    momentReaction.setOrientation(MOMENT_POSITIF);
                    momentReaction.setPointAction(position);
                    forceReactionIemeNoeud = [forceReactionIemeNoeud,momentReaction];
                end
            end  
        end

forceReactionIemeNoeud is the output parameter. But it is not set for

            if (typeAppui == SANS_APPUI)
                Force.empty(1,0);
            else

and so this code could (or should?) be

            if (typeAppui == SANS_APPUI)
                forceReactionIemeNoeud = Force.empty(1,0);
            else

This will ensure that something is returned that isn't empty.

The next piece of code to look at would be at

if(typeAppui == GOUPILLE || typeAppui == ENCASTREMENT)
    % some code
elseif(typeAppui == ENCASTREMENT)
    % some other code
end

Note how typeAppui == ENCASTREMENT is used for both. This would mean that if this is true, then the elseif will never be evaluated. Which of these conditions should be modified?

FInally, before we evaluate either of the above, we have already initialized

forceReactionIemeNoeud = [forceReactionIemeNoeud,forceReactionY]; 

so a "force" object is assigned here. But then we may do

forceReactionIemeNoeud = [forceReactionX,forceReactionIemeNoeud];  

which now sets forceReactionIemeNoeud to be an array of two force objects. Is this correct? Because I suspect that this would cause a problem when this is returned and we try to call getForceX.

[Charles-Antoine Danis]

at the line of the breakpoint after evaluate it, I got this error message

Index exceeds the number of array elements (16084).

Error in matlab.internal.editor.evaluateCode

[Geoff Hayes]

Have you changed your code? Because that is a different error from before...

[Charles-Antoine Danis]

yes I will reupload it

I change if type appuis = goupille

and

ForcereactionIemeNoeud

but you could see it in the file in attachment

[Geoff Hayes]

hmmm...I can look more closely in the morning but the error message

Index exceeds the number of array elements (16084). 

suggests that you are trying to use an index that is greater than 16084. What index are you using? Is this error coming from the getForcesReactionsIemeNoeud function? If so, you may need to guard against invalid indices

function [forceReactionIemeNoeud] = getForcesReactionsIemeNoeud(this,indiceNoeud)
Constantes;
forceReactionIemeNoeud = [];
if indiceNoeud <= length(this.noeuds)
    typeAppui = this.noeuds(indiceNoeud).getTypeAppui();
    if (typeAppui == SANS_APPUI)
        forceReactionIemeNoeud = Force.empty(1,0);
    else
        %etc.
    end
else
    forceReactionIemeNoeud = Force.empty(1,0);
end

[Charles-Antoine Danis]

ok thanks you a lot.