Question

I’ve been stumped trying to create an if,else loop that transposes the following:

Subject: Date: Result:
AAA 02/01/12 10
AAA 02/02/12 12
AAA 02/03/12 14
BBB 02/01/12 25
BBB 02/02/12 26
BBB 02/03/12 27
CCC 01/01/12 66
CCC 01/02/12 70
CCC 01/03/12 75

I desire the information to be transposed across columns as depicted below:

SUBJECT 01/01/12 01/02/12 01/03/12 02/01/12 02/02/12 02/03/12
AAA RESULT
BBB RESULT
CCC RESULT

There should only be one date per column and one subject per row. The result will match its respective subject and placed in its appropriate cell. The data can consist anywhere from a few subject to thousands of subjects, dates, and results. Some results may consist of non numerical values (NaN). Also, the subjects and dates may me in any random order and subjects may consist of numeric and string characters.

UPDATE
@amro & superbest

If I had a text file with the date format:800317==mar/17/1980,
How would I import this and modify the codes you’ve written?
THanks again.

Answer 1

Here’s a script which should do what you want:

% Clean up
clc
clear

% Hardcoded example input
input = {
    'AAA'    '02/01/12'    10
    'AAA'    '02/02/12'    12
    'AAA'    '02/03/12'    14
    'BBB'    '02/01/12'    25
    'BBB'    '02/02/12'    26
    'BBB'    '02/03/12'    27
    'CCC'    '01/01/12'    66
    'CCC'    '01/02/12'    70
    'CCC'    '01/03/12'    75
    };

% Figure out how many rows and columns there will be
header_row = unique(input(:, 2));
header_col = unique(input(:, 1));

% Pre-allocation for better performance
output = cell(length(header_col), length(header_row));

% Rearrange the array
for i = 1:size(input, 1)
    % Find to which date and subject this element belongs
    subject = find(strcmp(header_col, input{i, 1}));
    date = find(strcmp(header_row, input{i, 2}));

    % Put the value in the appropriate slot
    output{subject, date} = input{i, 3};
end

% Add header columns and rows and print the result
result = [['SUBJECT' header_row']; [header_col output]];