How to make Thresh_tool fucntion?

Hello everyones,

I have some code below:

%% Partition brain mass

%separate the brain mass into 2categories

level = thresh_tool(uint16(mriAdjust(:,:,20)),'gray');

mriBrainPartition=uint8(zeros(size(mriAdjust)));

mriBrainPatition(mriAdjust<level & mriAdjust>0)=2;

mriBrainPartition(mriAdjust>=3;

imshow(mriBrainPartition(:,:,20),[0 0 0;0 0 0;.25 .25 1;1 1 1]);

my code errored: Error using thresh_tool (line 67)

X must be same length as Y.

Please tranning for me how to make thresh_tool and fix code for me?

Thank you very much!