I can Not include my condition

Hi everybody,

my code produce some elements with x,y,z coordinates.

I want to put a condition that make them to have z limit, for example from z 0-100 there are some elements and also from z 100-200 there are some elements and so on but there is no element that is in both z limit area.

any suggestion will may be helpful and Thank you for that.

for i = 1:ne
     nodnum=zeros(1,nen);
     for j = 1 : nen
        check=Dof(:,1:nend)-ones(n,1)*Edof(i,(j-1)*nend+2:j*nend+1);
        [indx,dum]=find(check==0);
        nodnum(j)=indx(1);
     end
%       

          Ex(i,:)=Coord(nodnum,1)';
       if nsd>1
          Ey(i,:)=Coord(nodnum,2)';
       end
       if nsd>2    
          Ez(i,:)=Coord(nodnum,3)';
       end

    Le(i)=sqrt((Ex(i,1)-Ex(i,2))^2+(Ey(i,1)-Ey(i,2))^2+(Ez(i,1)-Ez(i,2))^2);

    end

[dpb]

Sorry, I can't follow what it is you've actually asking for here...can you give a small dataset that illustrates the problem and then what you want as a solution?

[Hamid]

thank you,

there are some 3-D coordinates for example

A=(0 0 0) B=(500 500 500) C=(500 500 1000) D=(500 500 1500)

these are start and end elements coordinates.

I want elements have z limit, it means from z 0-500 there are some coordinates and also from z 500-1000 there are some coordinates but I don't want an element that has a start in z<500 with an end in 500<z<1000 .

[Mohammad Abouali]

how can that even happen? I mean how can you have both z<500 and 500<z<1000 satisfied?

[Hamid]

we have 4 coordinates here therefore we have 6 elements, some of them can be deleted by this condition

[dpb]

Need more precise illustration of the dataset as it's stored and what it is you're actually asking for. Give a small sample that illustrates both the full input and the desired output.

We know you understand what your explanation means but we don't have the insider's knowledge to be able to read between the lines beyond what is actually provided here.

Answer 1

[Mohammad Abouali]

Ok, now I get it (I think).

You have four points, and lines connected between each two points are elements. (so in case of four points you have 6 elements or 6 lines).

Now You want only those lines (elements) that the ending points have z<500 or 500<z<1000 and not both. Pretty much you want your line to stay either under 500 elevation or in 500..1000 elevation and not cross the 500.

So, the solution depends a bit on how you store the elements. Let's say you have 4 points so point 1 to 4. Something like this should work:

clear; clc; close all;
P=[   0   0    0;
    500 500  500;
    500 500 1000;
    500 500 1500 ];

elements=[1 2; % defining start and end point
          1 3;
          1 4;
          2 3;
          2 4;
          3 4];

% this is your test function (I used <= instead of <)    
testFunc=@(x) ( all(P(x,3)<=500) || ...
                all(P(x,3)>=500 & P(x,3)<=1000) );

% this parts checks the condition.
elementsCell=mat2cell(elements,ones(size(elements,1),1),size(elements,2));
elementsMask=cellfun(testFunc,elementsCell);

disp('Elements satisfying the condition:')
disp(find(elementsMask))
disp('Elements end points:')
disp(elements(elementsMask,:))

Movafagh bashi

[Hamid]

you are the best,

Merci.