Cell array data to double conversion

Hi all,

I have a cell array that I want to transform to a double array. Then I would like to fill in the double array with data from cell arrays. To solve this problem I have tried two things:

• I have tried cell2mat, which gave a result that I couldent interpret and didnt work.
• I tried str2double, this does not give an error, but it writes only NaN values in the double array.

The names of the variables are

• Comp_all: cell array
• dat: translate cell to double
• dat2013: double array which I would like to fill in

How can I transfer both numeric and non-numeric data from cel arrays to double arrays?

The code is used to do this looks like:

dat = str2double(Com_all);


dat2013 = zeros(length(dat),5);
dat2013(1:end,1) = dat(1:end,1);

[the cyclist]

Can you upload the data (or a small subset) in a *.mat file, using the paper clip icon?

[Stephen23]

"How can I transfer both numeric and non-numeric data from cel arrays to double arrays?"

How do you expect non-numeric data to be represented in numeric arrays?

[Wouter Wizard]

@ the cyclist I have added the data here

@ Stephen Cobeldick

I think that would not be logical. But the first column of my cell array has names of countries. I would like to include these in the net double array. Is there a way to do this?

[Stephen23]

"But the first column of my cell array has names of countries."

Use a table. A table is probably the best way to store data with a header.

https://www.mathworks.com/help/matlab/matlab_prog/create-a-table.html

"I have added the data here"

You uploaded some code, but no data.

[Wouter Wizard]

Okay thanks Stephen, I wil try the table!

The Assignment2.m is in my previous comment. Sorry if this caused confusion, I am new and a bit unfamiliar with how to post questions and data.

[Wouter Wizard]

Another problem that I face is that I have the right information filtered in one of the cell arrays. I want to use that array as index for other cell arrays to extract the right data from it. However, I get an error that I cannot use a cell array for indexing.

To create input for the table I need the extracted data from the cell arrays. But I cannot translate the cell arrays into double arrays which allow indexing.

[Guillaume]

Stephen's advice: "Use a table. A table is probably the best way to [work with your type of data"

Note that I already gave you that advice (and plenty more...) several days ago in a question that you then deleted (so I completely wasted my time helping you).

Answer 1

[CAM]

Assuming each cell has only one entry, try using cellfun with str2double to convert the cell array of strings to a cell array of doubles, then use cell2mat.

Air code (untested; may need adjustment):

dblComp_all = cellfun(@str2double, Comp_all);
dat = cell2mat(dblComp_all);

[Stephen23]

Note that

cellfun(@str2double, Comp_all)

will only run without error if each cell returns a scalar, in which case it is exactly equivalent to calling str2double directly on the cell array (just more complicated).

Possibly you forgot 'UniformOutput',false.

[Wouter Wizard]

Thank you for replying CAM7, and providing a new code that I can test.

I tried to run the code and it gave this error:

Error in cell2mat (line 42)

cellclass = class(c{1});

Error in Assignment (line 55)

dat = cell2mat(dblCom_all);

[Wouter Wizard]

With a fresh look and some modifications in my data your answer results in the correct solution. The lines that work for me are:

data = cellfun(@(s) strrep(s, ' ', ''), data, 'UniformOutput', false);
dbldata = cellfun(@str2double, data);