Generate random short fiber in matlab?

Kindly look into the below code, i am not able to run it, if there is any issue.

function Fiber=Generate_Fiber(x,y,z,L,N)

%input

%x=[x1 x2]: x boundaries of the box
%y=[y1 y2]: y boundaries of the box
%z=[z1 z2]: z boundaries of the box
%L: Length of fibers
%N: Number of fibers

%output

%Fiber: (N,6) matrix of fiber coordinates with (:,1), (:,2) and (:,3) are x,y, and z coordinates of one end 
%and (:,4),(:,5) and (:,6) are x,y, and z coordinates of the other end.  

for i=1:1:N
    
    while 1
        
        x1=min(x)+(max(x)-min(x))*rand(1);
        y1=min(y)+(max(y)-min(y))*rand(1);
        z1=min(z)+(max(z)-min(z))*rand(1);
        
        theta=2*pi*rand(1);
        v=2*rand(1)-1;
        x2=x1+L*sqrt(1-v^2)*cos(theta);
        y2=y1+L*sqrt(1-v^2)*sin(theta);
        z2=z1+L*v;
        
        if x2<=x(2) && x2>=x(1) && y2<=y(2) && y2>=y(1) && z2<=z(2) && z2>=z(1)  
            break;
        end    
        
    end
    
    Fiber(i,1)=x1;
    Fiber(i,2)=y1;
    Fiber(i,3)=z1;
    Fiber(i,4)=x2;
    Fiber(i,5)=y2;
    Fiber(i,6)=z2;
    
end

Answer 1

[Dongyue]

Please try this

result = Generate_Fiber([0,1],[0,1],[0,1],0.5,2)

result = 2×6

0.2385 0.2689 0.0838 0.1044 0.6092 0.4247 0.3414 0.2479 0.6434 0.6763 0.0375 0.9493

function Fiber=Generate_Fiber(x,y,z,L,N)
    %input
    %x=[x1 x2]: x boundaries of the box
    %y=[y1 y2]: y boundaries of the box
    %z=[z1 z2]: z boundaries of the box
    %L: Length of fibers
    %N: Number of fibers
    %output
    %Fiber: (N,6) matrix of fiber coordinates with (:,1), (:,2) and (:,3) are x,y, and z coordinates of one end 
    %and (:,4),(:,5) and (:,6) are x,y, and z coordinates of the other end.  
    Fiber = zeros(N,6);
    for i=1:1:N
        while 1
            x1=min(x)+(max(x)-min(x))*rand(1);
            y1=min(y)+(max(y)-min(y))*rand(1);
            z1=min(z)+(max(z)-min(z))*rand(1);
            theta=2*pi*rand(1);
            v=2*rand(1)-1;
            x2=x1+L*sqrt(1-v^2)*cos(theta);
            y2=y1+L*sqrt(1-v^2)*sin(theta);
            z2=z1+L*v;
            if x2<=x(2) && x2>=x(1) && y2<=y(2) && y2>=y(1) && z2<=z(2) && z2>=z(1)  
                break;
            end    
        
        end
        Fiber(i,1)=x1;
        Fiber(i,2)=y1;
        Fiber(i,3)=z1;
        Fiber(i,4)=x2;
        Fiber(i,5)=y2;
        Fiber(i,6)=z2;
    end
end

[RAJESH]

Thank you but your code showing error>

>> Generate_Fiber

Not enough input arguments.

Error in Generate_Fiber (line 11)

Fiber = zeros(N,6);

Like this, Kindly into the matter.

[Walter Roberson]

The function to generate fibres is not designed to be called without any parameters. They gave an example of how to call the function,

result = Generate_Fiber([0,1],[0,1],[0,1],0.5,2)

[Walter Roberson]

@RAJESH

The code does run, provided that you call the function with proper parameters.

result = Generate_Fiber([0,1],[0,1],[0,1],0.5,2)

result = 2×6

0.0272 0.7726 0.8828 0.4877 0.9632 0.9230 0.6335 0.3202 0.8050 0.3940 0.4465 0.3847

function Fiber=Generate_Fiber(x,y,z,L,N)
    %input
    %x=[x1 x2]: x boundaries of the box
    %y=[y1 y2]: y boundaries of the box
    %z=[z1 z2]: z boundaries of the box
    %L: Length of fibers
    %N: Number of fibers
    %output
    %Fiber: (N,6) matrix of fiber coordinates with (:,1), (:,2) and (:,3) are x,y, and z coordinates of one end 
    %and (:,4),(:,5) and (:,6) are x,y, and z coordinates of the other end.  
    Fiber = zeros(N,6);
    for i=1:1:N
        while 1
            x1=min(x)+(max(x)-min(x))*rand(1);
            y1=min(y)+(max(y)-min(y))*rand(1);
            z1=min(z)+(max(z)-min(z))*rand(1);
            theta=2*pi*rand(1);
            v=2*rand(1)-1;
            x2=x1+L*sqrt(1-v^2)*cos(theta);
            y2=y1+L*sqrt(1-v^2)*sin(theta);
            z2=z1+L*v;
            if x2<=x(2) && x2>=x(1) && y2<=y(2) && y2>=y(1) && z2<=z(2) && z2>=z(1)  
                break;
            end    
        
        end
        Fiber(i,1)=x1;
        Fiber(i,2)=y1;
        Fiber(i,3)=z1;
        Fiber(i,4)=x2;
        Fiber(i,5)=y2;
        Fiber(i,6)=z2;
    end
end

[RAJESH]

Could you please provide me, some example code or tutorial for random fiber poistioning(RVE) and Generate random fiber?

[Rik]

If you have trouble with Matlab basics you may consider doing the Onramp tutorial (which is provided for free by Mathworks).