match vector with first column of matrix

I have a matrix 'Mat' and a vector 'v', I want to match the vector 'v' with the first row of 'Mat' such that I get an output 'res'. I tried using the ismember function and a code mentioned below

Mat=[1 356
 4 457
 7 91
 6 431
9 33
10 322  ]

v =[NaN 1 7 NaN 1  9 6 NaN 6 6]   

res= [NaN NaN
    1 356
    7 91
    NaN NaN
    1 356
    9 33
    6 431
    NaN NaN
    6 431
    6 431]


%%%%%%code I tried but did not work, it does not give numbers for repetative occurences of elemet in vector B
idx=setdiff(v,Mat(:,1)).';
ans=zeros(numel(idx),1);
idx=[idx' ans];
res=sortrows([Mat;idx]);

[SChow]

I tried a different code, but as the original length of v is 37324800x1 double, Matlab could not process the data

  v=v';

bsxfun(@minus,Mat(:,1),scode);
[~,minRow] = min(abs(bsxfun(@minus,Mat(:,1),v)));
res = [ v.', Mat(minRow,2:end) ];

Answer 1

[Stephen23]

Simpler with just one ismember call and some basic indexing:

>> [idx,idy] = ismember(v(:),Mat(:,1));
>> res = [v(:),v(:)];
>> res(idx,2) = Mat(idy(idx),2)
res =
   NaN   NaN
     1   356
     7    91
   NaN   NaN
     1   356
     9    33
     6   431
   NaN   NaN
     6   431
     6   431

Answer 2

[David Hill]

res=[v',nan(length(v),1)];
a=unique(v);
a=a(~isnan(a));
for j=1:length(a)
    res(ismember(v,a(j)),2)=Mat(ismember(Mat(:,1),a(j)),2);
end