How can I convert data in format cell to double?

How can I conver the data in format cell attached here to double? I tried function double. It works well for some of my data but not this file. I cannot not understand what is the difference.

Answer 1

[Star Strider]

You have to reference ‘G3’ specifically, then convert it.

This works:

d = load('Xinyuan Wei X.mat');
X = d.X;
G3 = X.G3;                                          % Define ‘G3’
G3_dbl = str2num(cell2mat(G3));                     % Convert ‘G3’ To Double

This is quite definitely not obvious! I had to experiment with it to get it to a double array.

[Guillaume]

I would advise against str2num as this evaluate arbitrary expressions in the string (including ones that wipe the hard drive!).

G3_dbl = str2double(G3);

is simpler anyway (does not need cell2mat)

[Star Strider]

Excellent point!

Thank you for the clarification. I didn’t consider that.

(I always read your and Andrei Bobrov’s Answers and Comments because I learn so much from them. Thank you for your continuing contributions to MATLAB Answers.)

Answer 2

[KSSV]

It is because..if you see your first dataset in X it is 'G3'. As it is a string, MATLAB is showing error to convert to double. You delete the first dataset 'G3' then double shall work.

[Xinyuan Wei]

</matlabcentral/answers/uploaded_files/54599/QQ%E6%88%AA%E5%9B%BE20160620212113.png> When I try to remove the varname 'G3', it gives out this error. Could you tell how to do this in detail? Thank you for your help.

Answer 3

[Shameer Parmar]

As the 'X' is in dataset format, so you need to create new variable by fetching data for 'X'.

first load your .mat file, then run the following code..

for i = 1: length(X)
    x(i) = str2num(X{i,1});
end
x = x';

Answer 4

[Xinyuan Wei]

Thank you so much for all your help.