Revision

**1d34d9c07e34cf0306445d49f7206994f5a79537**authored by James Scott on**19 July 2016, 08:40:22 UTC**, committed by James Scott on**19 July 2016, 08:40:22 UTC****1 parent**a7ab0a6

initialvalue.m

```
function initials=initialvalue(signalfile,zvaluefile,reglocafile,L)
%%L is number of the components in the normal mixture
signal=load(signalfile);%%%% signals, of the brain region of interest (ROI), gotten by BH procedure
zvalue=load(zvaluefile);%%%% observed data on the whole image grid including the brain part and the non-brain part
regloca=load(reglocafile);%%%%% location of the ROI on the LX*LY*LZ image grid
n_reg=length(regloca);% the number of voxels in the ROI
zvalue_1=zeros(n_reg,1);% to store the z-value of the signals by BH procedure
num=0;
for i=1:n_reg
pi=regloca(i);
if signal(i)==1
num=num+1;
zvalue_1(num)=zvalue(pi);
end
end
prop=1-num/n_reg;
%%%%%%%%%%%always use set the initial values for beta and h to be zeros
beta=0;
h=0;
initials=[beta,h];
temp=0;
try
obj=gmdistribution.fit(zvalue_1(1:num,1),L);%% gmdistribution.fit is a Matlab built-in function, see http://www.mathworks.com/help/stats/gmdistribution.fit.html
for j=1:L
initials=[initials,obj.mu(j),obj.Sigma(j),obj.PComponents(j)];
end
catch err %%%%%%% if gmdistribution.fit is divergent
mu=zeros(L,1);
if L==1
mu(1)=1;
elseif mod(L,2)==0 %%%%%%if L is divisible by 2, then let mu_i be [-L,-L/2,-L/4,...,L/4,L/2,L] and thus symmetric around 0.
temp=L/2;
for mu_i=1:temp
mu(mu_i)=mu_i*2;
mu(L-mu_i+1)=-mu(mu_i);
end
else %%%%%%%if L is not divisible by 2, then let mu_i be [-floor(L/2),-floor(L/2)+1,...,0,floor(L/2)-1,floor(L/2)] and thus symmetric around 0.
temp=ceil(L/2);
for mu_i=1:L
mu(mu_i)=mu_i-temp;
end
end
Sigma=ones(L,1);
PComponents=(1/L)*ones(L,1);
for j=1:L
initials=[initials,mu(j),Sigma(j),PComponents(j)];
end
end
```

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