Transferring variable names from one table to another

2020 8 14
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更新时间：2022 8 25
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I'm trying to use the variable names of one of my tables in another new table, but keep getting an error saying "Error using table The VariableNames property is a cell array of character vectors. To assign multiple variable names, specify names in a string array or a cell array of character vectors" even though I have the variable names saved in a cell array. I have tried making varnames a string array, used a for loop to copy all the names to varnames, concatenated them vertically instead of horizontally just for the heck of it, but I can't seem to figure it out. This is my code:
varnames = cell.empty;
varnames = DataFinal.Properties.VariableNames
T = table('VariableNames',{varnames}, 'RowNames', {'A','B','C'})

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Walter Roberson
Walter Roberson 2020-8-14

0 个投票

varnames = DataFinal.Properties.VariableNames
T = table('VariableNames',varnames, 'RowNames', {'A','B','C'})

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Walter Roberson
Walter Roberson 2020-8-14
I think you are going to have trouble with the RowNames. There should be one row name for each row, but you are creating a table with no rows.
Kanak Gupta
Kanak Gupta 2020-8-16
Thank you! Realized I had to define the sizes and thus the variable types and so on, ended up with this, and it works! Thanks again!
vartype = cell(1,49)
for j=1:49
vartype{1,j} = 'double'
end
varnames = PatientDataFinalwithv11.Properties.VariableNames(2:50)
T = table('Size',[12 49],'VariableTypes', vartype,'VariableNames',varnames, 'RowNames', {'Intercept Es...'})
Jonathan Thompson
Jonathan Thompson 2022-8-20
Hello,
I tried this method on MATLAB R2020B and received the following error:
Error using table (line 335)
The VariableNames property must contain one name for each variable in the table.
The varnames variable I created is a cell array with names from a table I imported with readtable. So, I believe I've followed all of the prerequisits for the two lines of code shown above to work. Any thoughts?
Walter Roberson
Walter Roberson 2022-8-23
Ran in:
Ran in:
N = 49;
vartype = repmat({'double'}, 1, 49);
varnames = "MyVar" + (1:N);
T = table('size', [12 N], 'VariableTypes', vartype, 'VariableNames', varnames);
whos T
Name Size Bytes Class Attributes T 12x49 16331 table
Walter Roberson
Walter Roberson 2022-8-23
Ran in:
Ran in:
@Jonathan Thompson
If you have a list of variable names and you want to allocate a table of that size, then (for example)
varnames = "MyVar" + (1:randi(50)); %variable names read from table
nrows = 7; %for example
N = length(varnames);
vartype = repmat({'double'}, 1, N);
T = table('size', [nrows N], 'VariableTypes', vartype, 'VariableNames', varnames);
whos T
Name Size Bytes Class Attributes T 7x28 8533 table
Jonathan Thompson
Jonathan Thompson 2022-8-24
@Walter Roberson
Thanks. It seems that the use of repmat only allows one data type. I suppose that if I need to have columns of different data types, I can just change those columns after the table is created, right?
Walter Roberson
Walter Roberson 2022-8-25
repelem({'double', 'categorical', 'double'}, 1, [17, 2, 11])
for example for the case of 17 double followed by 2 categorical followed by 11 double

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