# How can I print the result of a function using fprintf? (matrix and string!)

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Ashley Hayden on 18 Mar 2020
Commented: Ashley Hayden on 18 Mar 2020
The variable countries is a 27x1 column vector with 3 letter abbreviations (ex. 'CAN'). Results is a 27x4 matrix with values ranging from 0-40 ish. Why can't I print them together or row by row?
I want the result to look like this:
Country Gold Silver Bronze
CAN 2 1 3
ITA 3 1 4
... etc.
My code:
function [] = Untitled6()
results = zeros(size(countries,1),4);
results = compute_medals(gold,silver,bronze,countries);
print_country_results(countries,results);
end
function results = compute_medals(gold,silver,bronze,countries);
% computes number of gold, silver, bronze medals and
% total medal tally for a given country and a given sport type
% results = zeros(size(countries,1),4);
for i = 1:length(countries)
country = countries(i, :);
goldCount = 0;
silverCount = 0;
bronzeCount = 0;
for j = 1: length(gold)
if country == gold(j, :)
goldCount = goldCount+ 1;
end
if country == silver(j, :)
silverCount = silverCount + 1;
end
if country == bronze(j, :)
bronzeCount = bronzeCount + 1;
end
end
results(i,1) = goldCount;
results(i,2) = silverCount;
results(i,3) = bronzeCount;
results(i,4) = goldCount + silverCount + bronzeCount;
end
results
end
function [ ] = print_country_results(countries,results)
% prints formatted results
fprintf('Country Gold Silver Bronze Total\n')
for i = 1:length(countries) % = 27
fprintf('%s %d \n', countries(i, :), results (i,:));
end
end
EDIT: We are not allowed to use a table. :(

James Tursa on 18 Mar 2020
What is the variable 'countries'? I.e., class. Same question for gold, silver, bronze.
Ashley Hayden on 18 Mar 2020
Countries (27x3) is a char class. Gold, silver, and bronze are also char class. I have attached the file with all the starting variables (olympics.mat). They look like this:
'AUS'
'AUT'
'BLR'
'CAN'
'CHN'
'CRO'
'CZE'
'EST'
'FIN'
'FRA'
'GBR'
'GER'
'ITA'
'JPN'
'KAZ'
'KOR'
'LAT'
'NED'
'NOR'
'POL'
'RUS'
'SLO'
'SUI'
'SVK'
'SWE'
'USA'
'XXX'

Ameer Hamza on 18 Mar 2020
Edited: Ameer Hamza on 18 Mar 2020
You can change your function like this
function [ ] = print_country_results(countries,results)
% prints formatted results
fprintf('Country\tGold\tSilver\tBronze\tTotal\n')
for i = 1:length(countries) % = 27
fprintf('%s\t%d\t%d\t%d\t%d\n', countries(i, :), results (i,:));
end
end
Output:
Country Gold Silver Bronze Total
AUS 2 1 0 3
AUT 4 6 6 16
BLR 1 1 1 3
CAN 14 7 5 26
CHN 5 2 4 11
CRO 0 2 1 3
CZE 2 0 4 6
EST 0 1 0 1
FIN 0 1 4 5
FRA 2 3 6 11
GBR 1 0 0 1
GER 10 13 7 30
ITA 1 1 3 5
JPN 0 3 2 5
KAZ 0 1 0 1
KOR 6 6 2 14
LAT 0 2 0 2
NED 4 1 3 8
NOR 9 8 6 23
POL 1 3 2 6
RUS 3 5 7 15
SLO 0 2 1 3
SUI 6 0 3 9
SVK 1 1 1 3
SWE 5 2 4 11
USA 9 15 13 37
XXX 1 0 2 3

#### 1 Comment

Ashley Hayden on 18 Mar 2020
Thank you! Good to know I only missed something simple.

James Tursa on 18 Mar 2020
Edited: James Tursa on 18 Mar 2020
When comparing strings, it is not a good idea to use the == operator, which is an element-wise operator. Instead, use a string comparison function or a general comparison function. E.g., instead of this
if country == gold(j, :)
do something like this
if isequal( country, gold(j, :) )
or maybe
if strcmpi( country, gold(j, :) )
Also, in your print statement you need to print four numerical values, not one. E.g. this
fprintf('%s %d \n', countries(i, :), results (i,:));
should be something like this instead
fprintf('%s %7d %6d %6d %5d \n', countries(i, :), results (i,:));

Adam Danz on 18 Mar 2020
Put the data into a table and display the table. There are lots of way to create a table. Here's one way,
data = [2 1 3; 3 1 4];
T = array2table(data, 'VariableNames', {'Gold','Silver','Bronze'}, 'RowNames', {'CAN','ITA'});
To display it,
disp(T)

#### 1 Comment

Ashley Hayden on 18 Mar 2020
I should've mentioned it in the question itself - I'm not allowed to use a table. Is there a way I can use fprintf?