Returning Multiple Variables from a function to be added to existing variable.

I have a function below that returns multiple variables/matrices seen below. Rather than returning to the variable K_1 i would like to add its contents to an existing variable K. I am unsure how to do this when returning multiple variables and still want to return to the other variables.

[k_1,K_1,B1,b1,c1]=element_stiffness([2,4,1],Coords, v,E,t,D)

Answer 1

[Jan]

What about:

[k_1,K_1,B1,b1,c1]=element_stiffness([2,4,1],Coords, v,E,t,D)
k = [k, k_1];

% Or:
k = k + k_1;

% Or:
k = zeros(5, 100);  % Pre-allocate
for i = 1:5
  [k(i, :), K_1,B1,b1,c1]=element_stiffness([2,4,1],Coords, v,E,t,D)
end

[Simon Cook]

I did consider using a temporary dummy variable as you have demonstarted in the 1st case. However was looking to implement this slightly differently. If just a single variable were returned I imagine something like this (syntax wont run on matlab) but im not sure.

K+=element_stiffness()

[Jan]

If only the first output of the function matters, this is a valid Matlab syntax:

k = k + element_stiffness()

Answer 2

[Image Analyst]

What about

[K(end+1), K_1, B1, b1, c1] = element_stiffness([2,4,1],Coords, v,E,t,D)

This puts the return variable into an element at the end of the K vector. An additional element is created. So if K was [213, 4234] then after calling this if k_1 was 999, the new K would be [213, 4234, 999].

[Simon Cook]

I think i may have phrased my question poorly rather than concatenating I mean adding the numerical values (in this case K/K_1 is a 10x10 matrix) of the matrix returned from the function to the 10x10 matrix.

K=zeros(10)

%I want to achieve K=K+K_1 however when returning from the function

%This may work but wondered if it could be achieved when directly returning
%from the function
[Temp_variable,A1,B1]=element_stiffness()
K=K+Temp_variable%

%K should now have 1 added to each element. Other variable should be
%returned as normal

function  [K_1,A,B]=element_stiffness()
    K_1=ones(10)
    A=1
    B=2
end

[Image Analyst]

Sure, if K_1 and K are 2-D 10x10 matrices, then you can certainly return a temporary variable K_1, and then add that to K like you did.

But you have to do it in MATLAB syntax

K = K + Temp_variable;

not C syntax

K += Temp_variable

The size and shape of Temp_variable has to match that of K of course.