Plot columns against each other depending on user input from imported excel file.

Hi,

I would like to plot the total_cases against days_tracked based on the country that is inputted by the user. The plotting of data is dependent on which country is inputted by the user, however if I for example put Australia as an input it does not plot.

I'm not sure if I have formatted the strcmpi properly as this might be where the problem is. I can't attached the excel file as it exceeds 5MB even as a zip file.

Thanks

covid_data = readtable('owid-covid-data.xlsx');

%Extracting columns from excel
Total_cases = covid_data{:,6};
Days_tracked = covid_data{:,5};
Total_deaths = covid_data{:,9};
New_cases = covid_data{:,7};
New_deaths = covid_data{:,10};
Location = covid_data{:,3};
user_input= input('Please input a valid country','s'); 

all_countries = covid_data;
if strcmpi(user_input,Location)
    plot(Days_Tracked,Total_cases)
else 
    fprintf('error')
end 

[dpb]

You read the data in as a table; use it instead of creating all new variables.

We don't know what the data are by type; the Location as a cell-string or char string would be ideal candidate to turn into a categorical variable for which can use equality "==" operator. Or, you could make it simpler for the user by giving them a selection from which to choose instead.

Your comparison as written will return an array comparing to the entire vector; you then do nothing to use that to select the subset of data and in MATLAB an IF is True iff all elements of an array are true; hence, unless the data are only those for the chosen country, the test will never match as written.

The whole spreadsheet may be too big, there's certainly nothing preventing saving a representative subset and attaching it --

Answer 1

[VBBV]

See the solution in the below link

https://in.mathworks.com/matlabcentral/answers/621968-need-help-plotting-things-from-a-table?s_tid=srchtitle

[Cate may]

Thank you, this link was very helpful.

I implemented the edits into my code however now I get an error saying it doesn't recognise my variable 'total_cases' and an error in total_cases(total_cases == 0) = [].

I dont understand why it doesn't recognise my variable because I've defined it with the correct column of data.

I have attached a sample of the excel data sheet.

 
covid_data = readtable('owid-covid-data.xlsx');

%Extracting columns from excel
% Total_cases = covid_data{:,6};
% Days_tracked = covid_data{:,5};
% Total_deaths = covid_data{:,9};
% New_cases = covid_data{:,7};
% New_deaths = covid_data{:,10};

user_input= input('Please input a valid country','s'); 
Location = covid_data(:,3);
CC = table2cell(Location);
CC1 = table2cell(covid_data);
[R C] = size(covid_data);

for i = 1:R
    if strcmp((CC(i)),(user_input));
        total_cases(i)=cell2mat(CC1(i,6));
        days_tracked(i) = cell2mat(CC1(i,5));
    end 
end 
 total_cases(total_cases == 0) = [];
 days_tracked(days_Tracked == 0) = [];
plot(days_tracked, total_cases)

[VBBV]

Try this code, it works,

the userinput had to entered without space.

clearvars
clc
covid_data = readtable('owid-covid-data.csv');

% Extracting columns from excel
% Total_cases = covid_data{:,6};
% Days_tracked = covid_data{:,5};
% Total_deaths = covid_data{:,9};
% New_cases = covid_data{:,7};
% New_deaths = covid_data{:,10};
%totalcases = [];
%daystracked = [];

user_input= input('Please input a valid country:  ','s'); 
Location = covid_data(:,3);
CC = table2cell(Location);
CC1 = table2cell(covid_data);
[R C] = size(covid_data);

for i = 1:R
    if strcmp(CC(i),user_input);
        totalcases(i)=cell2mat(CC1(i,6));
        daystracked(i) = cell2mat(CC1(i,5));
    end 
end 
totalcases(totalcases == NaN) = [];
daystracked(daystracked == NaN) = [];
plot(daystracked, totalcases)

[Cate may]

Yes! Thank you!!