Grey Slicing Image Function

I am trying to create a function to grey slice images using this piecewise function given by my professor:

I am running into some issues right now with setting the intensity values.

function outImage = baker10(inImage, intensities)

% convert input image to grayscale
grayImage = colorToGray(inImage);

% obtain the image size
[M, N, P] = size(grayImage);

% convert image to type double for MATLAB operations
tempim = double(inimage);

% create space for the grayscale image
outImage = zeros(M,N,3);

intensities[

% the image is converted to gray-scale by making setting RGB equal
% to the intensity of the pixel
for m = 1 : 1 : M
    for n = 1 : 1 : N
        for p = 1 : 1 : P
        if tempim(m,n,p) < intesities(m)
            outImage(m,n,p) = 0;
        elseif tempim(m,n,p) >= intensities(m) && tempim(m,n,p)...
                <= intensities(n);
            outImage(m,n,p) = intensities(m,n,p);
        else tempim(m,n,p) > intensities(n)
            outImage(m,n,p) = 0;
        end
        end
    end

% convert image back to type uint8
outImage = uint8(outImage);
outImage = outImage * 255;

end