Copying rows from one table to another

I have a large table of data which I have managed to filter down to the particular entrees I want by deleting unwanted rows. I'd like to be able to create new tables off of this.

For example making a new table consisting off all rows in the original that have the entree X for field y.

I would like to use this with a logical expression such as

rows = table.Name == 'Smith';
vars = {'Gender','Height','Weight'};
newTable = table(rows,vars)

However when do this it informs me that "==" is not defined for cells. What is the correct way to do this?

Answer 1

[Alexandra Harkai]

strcmp(table.Name, 'Smith')

would do the trick.

[Alexandra Harkai]

For more generic table indexing, see:

https://uk.mathworks.com/help/matlab/matlab_prog/access-data-in-a-table.html

For the '0-1' logical indexing see:

https://uk.mathworks.com/help/matlab/math/matrix-indexing.html?searchHighlight=logical%20indexing#bq7egb6-1

So in your example this would work:

newTable = table(rows,:);

This gives you all the vars for the selected rows. Just a small observation: you may want to use a different name for your original table named 'table' to avoid confusion with the function also named 'table'.

[David Cynamon]

Thank you very much for the help!

I saw in the first link you sent that I could use code like the following to return a structure where cells that have entries greater than specific values are listed.

rows = T.Var2>0;

However when I try this I get "Undefined operator '>' for input arguments of type 'cell'". What command would let me do this?

Thank you again for your help, it's much appreciated.

[Alexandra Harkai]

If your table column for a given variable is a cell array, then you need to get the data 'out' of it: http://uk.mathworks.com/help/matlab/cell-arrays.html

So cell2mat would 'Convert cell array to ordinary array of the underlying data type'.