function [prefix] = get_Prefix(inputIP,mask)

maskTmp = zeros(1,4);
    
    
    for i=1:4
        if mask >= 8
            maskTmp(i) = 255;
            mask = mask-8;
        elseif mask ==0
            maskTmp(i) = 0;
        else
            tmp=zeros(1,8);
            tmp(1:mask)=1;
            maskTmp(i) = sum(tmp.*2.^(numel(tmp)-1:-1:0));
            mask=0;
        end
            
    end
    mask=maskTmp;
    
    numIP= convert_IP(inputIP);
    if numIP ~=-1
        prefix = bitand(numIP,mask);
        prefix = convert_IP(prefix);
    end
end

           other file 

function [DNS_set] = prefixList(DNS_set,inputIP,mask,mode)
 


 %LOading of IPList%

 fileName='prefixList.m';
fileID = fopen(fileName,'r');

  
load('DNS_set_2014_03_06_B.mat');

IPList = DNS_set.IPList;

  [prefix] = get_Prefix(IPList,24);
 
prefixMap=DNS_set.prefixMap;
 prefixList = DNS_set.prefixes;
  prefixNumber = size(prefixList,1)+1;

if prefixMap.isKey(prefix)==false
            prefixMap(prefix) = prefixNumber;
            prefixNumber = prefixNumber +1;
            prefixList = [prefixList;{prefix}];
            for i=1:numel(inputIP)                                             
                inputIP{i} =[inputIP{i},zeros(size(inputIP{i},1),1)];
            end
            
  end

 prefixList = DNS_set.prefixList;

   end 


Can you please me why this error occurs?
thanks in advance

<surajparab945@gmail.com> wrote in message 
news:bf80639e-f4b6-40e3-a8a3-5053cc039fda@googlegroups.com...
>
> function [prefix] = get_Prefix(inputIP,mask)
>
> maskTmp = zeros(1,4);
>
>
>    for i=1:4
>        if mask >= 8
>            maskTmp(i) = 255;
>            mask = mask-8;
>        elseif mask ==0
>            maskTmp(i) = 0;
>        else
>            tmp=zeros(1,8);
>            tmp(1:mask)=1;
>            maskTmp(i) = sum(tmp.*2.^(numel(tmp)-1:-1:0));
>            mask=0;
>        end
>
>    end
>    mask=maskTmp;
>
>    numIP= convert_IP(inputIP);
>    if numIP ~=-1
>        prefix = bitand(numIP,mask);
>        prefix = convert_IP(prefix);
>    end
> end

What does this code do if numIP turns out to be -1? What value is assigned 
to the prefix output variable? What value should be returned to the function 
that called get_Prefix?

*snip*

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slord@mathworks.com
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