How to Iterate over the columns of a Matlab table?
203 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Ciaran
am 25 Okt. 2015
Kommentiert: Image Analyst
am 8 Sep. 2020
How can I iterate over the columns of a Matlab table? The Python equivalent and assuming data was a pandas data frame would be:
variable_names=data.keys() #get variable names
for i in variable_names: # iterate over and print all data using variable names
print data[i]
But the corresponding for a Matlab table does not work:
f='Vilar_data.xls';
data=readtable(f);
variables=data.Properties.VariableNames; %get variable names
for i=variables,
data(1:end,{i}) %attemt to iterate over the data by column headings
end
1 Kommentar
Oleg Komarov
am 25 Okt. 2015
You need to remove the brackets from {i}, because i will already be a cell containing a string.
Akzeptierte Antwort
Geoff Hayes
am 25 Okt. 2015
Bearbeitet: Geoff Hayes
am 25 Okt. 2015
Ciaran - access data in a table illustrates a couple of different ways in which you can access the column data within the table. You can access the column either by its variable index or by its variable name. For example, if you wish to access each column by the variable index, you could something like the following
for k=1:length(variables)
colData = data.(k);
end
In the above, we iterate over each variable and access the column data directly through the variable index.
3 Kommentare
Maryam Abbaszadeh
am 8 Sep. 2020
x = [];
x = ['A':'Z'];
for i='A':'Z'
for j='A':'Z'
x = [cellstr(x),[i,j]];
end
end
for i=1:100
app.UITable.ColumnName ={x(i)};
end
i want to change ColumnNames with x characters but it doesn't work with above code
how can I solve this problem?
Image Analyst
am 8 Sep. 2020
No idea what you want. Please read this link then post your question in a new question along with your desired output.
Weitere Antworten (2)
Image Analyst
am 25 Okt. 2015
I would not iterate over variable names, unless they might possibly be created by some weird program that changes what column the data were in. I'd simply just use column number - it's so so much simpler. Run this demo:
% Create sample data (from the help documentation).
LastName = {'Smith';'Johnson';'Williams';'Jones';'Brown'};
Age = [38;43;38;40;49];
Height = [71;69;64;67;64];
Weight = [176;163;131;133;119];
BloodPressure = [124 93; 109 77; 125 83; 117 75; 122 80];
% Create a table, T, as a container for the workspace variables.
T = table(Age,Height,Weight,BloodPressure,'RowNames',LastName)
% Let's see what methods T has
methods(T)
% Now let's iterate over all columns using column number.
for col = 1 : width(T)
fprintf('\nHere is column #%d, which is called %s\n', col, T.Properties.VariableNames{col})
thisColumn = T(:, col) % Extract this one column into its own variable.
% Now do whatever you want with "thisColumn" variable.
end
2 Kommentare
Image Analyst
am 26 Okt. 2015
I don't think so. Plus it's way more complicated. Why do you think it's better? My code will work with any table just using a simple index like you're already used to with other variable types. I'm not sure why you imply my code won't "take any table." It certainly will, and in a lot more straightforward manner.
Siehe auch
Kategorien
Mehr zu Logical finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!