How can i use a loop for text and numbers ?
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Hello,
I have some data presented in 3 columns (Company_name/Bank_name/Bank_investment_in_company)
It looks like that:
['CompA','BankA',10;
'CompA','BankB',30;
'CompB','BankA',5;
'CompB','BankD',8;
'CompB','BankC',12;
'CompC','BankB',15]
I would like to know for each Company (CompA,CompB,CompC) who invested the most money (BankA...) and present it in a table.
How can i do? I also want to present the result in a table.
Thank you very much!
回答（2 个）
A "brute force" engine...
>> x=[1 1 10;1 2 30;2 1 5;2 4 8; 2 3 12; 3 2 15]; % convert A,B,C,... --> numeric
>> C='A':'C'; % company IDs --> number
>> B='A':'D'; % ditto banks
>> [u,ia]=unique(x(:,1)); % get unique companies, positions
>> ia=[0;ia]; % and a 0 start location for first to begin loop
>> for i=1:length(u) % for each company
[mx,ix]=max(x(ia(i)+1:ia(i+1),3)); % get banks invested values and find max, which in group
ix1=ix+ia(i); % position in group to position in array
sprintf('Comp%c Bank%c Invest $%2dM\n',C(i),B(x(ix1,2)),x(ix1,3)) % show output
end
ans =
CompA BankB Invest $30M
ans = CompB BankC Invest $12M
ans = CompC BankB Invest $15M
>>
Above can be turned into anonymous function and arrayfun build the final array instead of just printing output on the fly. Similar can be done w/ data types of nominal variables but I have to futz with them to get syntax right; can't just write on-the-fly code. (OK, I will admit that the same logic loop occurred just earlier today in another answer so all I had to do was substitute variables and a second index into a previous answer...it took me a couple passes earlier to get the indirect references right. :) )
ADDENDUM
On the array directly building an output table...
>> for i=1:length(u)
[mx,ix]=max([data{ia(i)+1:ia(i+1),3}]);
ix1=ix+ia(i);
out(i,1)={sprintf('%s %s Invest $%2dM\n', ...
data{ix1,1},data{ix1,2},data{ix1,3})};
end
>> [out{:}]
ans =
CompA BankB Invest $30M
CompB BankC Invest $12M
CompC BankB Invest $15M
>>
Can't use an anonymous function, however, as can't return the optional second return value from max nor make the secondary fixup of the index so would have o have a helper two-liner function for arrayfun to work with.
yem
2015-4-22
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1 个评论
I've only used the dataset a very little and only for regular data so I don't have any insight there, sorry. I found grpstats problematical at best owing to a penchant I found for it to want to reorder variables on output on its own so I abandoned it and haven't gotten a more recent version to see if the bug has been fixed in later versions (I've R2012b)
NB: the above logic engine can be applied to the cell array, too...
>> data={'CompA','BankA',10;
'CompA','BankB',30;
'CompB','BankA',5;
'CompB','BankD',8;
'CompB','BankC',12;
'CompC','BankB',15};
>> [u,ia]=unique(data(:,1))
u =
'CompA'
'CompB'
'CompC'
ia =
2
5
6
>>
Those are the same indices ia as returned from the numeric-only version but with the cell string IDs already there so you can refer to the results directly.
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