MATLAB: Changing table columns to the same type

urlread

I am downloading data from the internet using 'urlread' function. I am using this to analyse football stats for my betting. So there are columns for HomeTeam, AwayTeam, Shots, Possesion etc.. I want all these columns to be of the same type! Preferably just numbers. I tried doing a for loop with if statements trying to highlight certain columns to change them from, say, 'Arsenal' to just a 1. (This is because arsenal is first alphabetically) So something like
for ii=1:height(data) % This makes sure it goes through all the rows. ./
if data(ii,1)=='Arsenal' 
data(ii,1)=1; %Data is just matrix with statistics.  
 end
end
The error message I get is ''Undefined operator '==' for input arguments of type 'table'.''

Best Answer

There are several errors that you're making.
For a start, () indexing on tables return tables. You would have to use {} to actually get to the content of the column. So:
data{ii, 1}
Secondly, you cannot use == to compare strings. You have to use strcmp. So:
if strcmp(data{ii, 1}, 'Arsenal')
But possibly, the biggest error, is to use a loop and lots of if to do something that could be done in only two lines:
[~, ~, uids] = unique(data{:, 1}); %change the strings into unique ids alphabetically
data.(data.Properties.VariableNames{1}) = uids;
Note that if you use column names it's even simpler:
    [~, ~, uids] = unique(data.NameOfFirstColumn);
  data.NameOfFirstColumn = uids;
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