MATLAB: Loading and naming specific columns

data structurefor loop

Hello,

I used this code to import and name data in Matlab:

for i=1951:2000
fileName=['arunoff_' num2str(i)];
dataStruct.(fileName)=importdata([fileName '.txt']);
end

This creates data structure dataStruct.arunoff_(i).data for each year (1951-2000). Next I would like to create and name another set of variables using the third column in 'data' (i.e. dataStruct.arunoff_1951.data(:,3), dataStruct.arunoff_1952.data(:,3) etc.). However, I don't know how to write a loop that does that and was wondering if someone could help me with this? My main problem is I don't know how to tell the loop to use data in each a_runoff(i) structure.

Hope this makes sense, thanks very much for the help!

Best Answer

fn = fieldnames(dataStruct);
for K = 1:length(fn)
  newStruct.([fn 'd3']) = dataStruct.(fn).data(:,3);
end

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MATLAB: Removing structure field if

fn1 = fieldnames(Struct1);
fn2 = fieldnames(Struct2);
tf = ismember(fn2, fn1);
NewStruct = struct();
for K = 1 : length(tf)
  if tf(K); NewStruct.(fn2{K}) = Struct2.(fn2{K}); end
end

I expect that is also a vectorized formulation that uses struct2cell()

MATLAB: Storing tables in an array and calling them whithin a for loop

You've shown your data, but that can't possibly be output from MATLAB because

'AAPL' =

is not something MATLAB would ever display. I'm gonna assume you've done something like

aapl = readtable('aapl.csv');
axp = readtable('axp.csv');
...

It's almost never a good idea to try to do this via an eval. A reasonable thing to do might be to use a scalar struct with fields named 'aapl', etc. So

data.aapl = readtable('aapl.csv');
data.axp = readtable('axp.csv');

and then

fn = fieldnames(data);
for i = 1:length(fn)
    for j = 1:length(fn)
        ret_1 = data.(fn{i}).Return;
        ret_2 = data.(fn{j}).Return;
    end
end

Best Answer

Related Solutions

MATLAB: Removing structure field if

MATLAB: Storing tables in an array and calling them whithin a for loop

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