Can I return the last two values of this function ONLY? Or must I return them all? I know I can return the first easily enough, but what about the second, and third, etc???

    function [m,b,Sm,Sb,CoVar,r]=ErrorCalc_SLF(X,Y)
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %This function takes in two measurements. It then calculates
    %the slope and intercept of the best fitting line and returns
    %these values, with slope=m and intercept=b, as well as  the
    %the error in m and b.
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    n=numel(X);
    if n~=numel(Y)
        Err='The data arrays do not have the same number of elements, please correct';
        disp(Err);
    else
        Sx=sum(X);
        Sy=sum(Y);
        XY=linspace(0,0,n);
        XX=linspace(0,0,n);
        YY=linspace(0,0,n);
        YBMX=linspace(0,0,n);
        DiffX=linspace(0,0,n);
        DiffY=linspace(0,0,n);
        ProdDXDY=linspace(0,0,n);
        D2X=linspace(0,0,n);
        D2Y=linspace(0,0,n);
        for i=1:n
            XY(i)=X(i)*Y(i);
            XX(i)=X(i)*X(i);
            YY(i)=Y(i)*Y(i);
        end
        Sxx=sum(XX);
        Sxy=sum(XY);
        Syy=sum(YY);
        Del=n*Sxx-Sx^2;
        m=(n*Sxy-Sx*Sy)/Del;
        b=(Sxx*Sy-Sx*Sxy)/Del;
        for i=1:n
            YBMX(i)=Y(i)-b-m*X(i);
        end
        Sybmx=sum(YBMX);
        SigY=sqrt((1/(n-2))*Sybmx^2);
        Sm=SigY*sqrt(n/Del);
        Sb=SigY*sqrt(Sxx/Del);
        %THIS IS THE NEW CODE----
        Xbar=sum(X)/n;
        Ybar=sum(Y)/n;
        for i=1:n
            DiffX(i)=X(i)-Xbar;
            DiffY(i)=Y(i)-Ybar; 
            ProdDXDY(i)=DiffX(i)*DiffY(i);
            D2X(i)=DiffX(i)^2;
            D2Y(i)=DiffY(i)^2;
        end

        CoVar=(1/n)*sum(ProdDXDY);
        r=(sum(ProdDXDY))/(sqrt(sum(D2X)*sum(D2Y)));
    end
    end

Answer 1

[Matt J]

The code for ErrorCalc_SLF must return them all, but the workspace that invokes the function doesn't have to receive them all. It can invoke the function like this

[~,~,~,~,CoVar,r]=ErrorCalc_SLF(X,Y)

in which case the first 4 outputs will be discarded.

[Francesco De Chellis]

Perfect! That is exactly what I needed!! Thank you!!!