Use regexprep with cell array for colons to format - string

Question

I have a cell array formatted as:
t = {'23:34:22.959511';
'22:34:11.885113';
'12:34:08.995146';
'11:34:02.383092'}
I am trying to format the output as 4 column vectors as:
a = 23
22
12
11
b = 34
34
34
34
c = 22
11
08
02
d = 959511
885113
995146
383092
I am using regexprep to operate on the data:
a = regexprep(t,':34:22.959511', '')
However this only pertains to only one string in the data set and not all strings.
How do I divide the string into 4 column vectors -- using regexprep for colon: and display the output below?

Answer 1

If you're willing to use other solutions that regexp: strplit can split on any desired character:
a = zeros(numel(t),1);
b = zeros(numel(t),1);
c = zeros(numel(t),1);
d = zeros(numel(t),1);
for ii = 1:numel(t)
C = strsplit(t{ii}, ':');
a(ii) = str2double(C{1});
b(ii) = str2double(C{2});
tmp = strsplit(C{3},'.'); % Additional split for dot
c(ii) = str2double(tmp{1});
d(ii) = str2double(tmp{2});
end
Of course this only works when your data always has this structure (two colons, then one dot)

Answer 2

Here's a way:
r = cell2mat(cellfun(#str2double, regexp(t, ':|\.', 'split'), 'uniformoutput', false));
This gives
r =
23 34 22 959511
22 34 11 885113
12 34 8 995146
11 34 2 383092
If you really need four separate variables, you can use:
r = num2cell(r,1);
[a, b, c, d] = r{:};

Answer 3

I would recommend using split instead of strsplit. split will operate on vectors and if you use the string datatype you can just call double on the string to get the numeric value
>> profFunc
Adriaan's Solution: 5.299892
Luis Mendo's Solution: 3.449811
My Solution: 0.094535
function profFunc()
n = 1e4; % Loop to get measurable timings
t = ["23:34:22.959511";
"22:34:11.885113";
"12:34:08.995146";
"11:34:02.383092"];
tic
for i = 1:n
a = zeros(numel(t),1);
b = zeros(numel(t),1);
c = zeros(numel(t),1);
d = zeros(numel(t),1);
for ii = 1:numel(t)
C = strsplit(t{ii}, ':');
a(ii) = str2double(C{1});
b(ii) = str2double(C{2});
tmp = strsplit(C{3},'.'); % Additional split for dot
c(ii) = str2double(tmp{1});
d(ii) = str2double(tmp{2});
end
end
fprintf('Adriaan''s Solution: %f\n',toc);
tic
for i = 1:n
r = cell2mat(cellfun(#str2double, regexp(t, ':|\.', 'split'), 'uniformoutput', false));
r = num2cell(r,1);
[a, b, c, d] = r{:};
end
fprintf('Luis Mendo''s Solution: %f\n',toc);
tic
for i = 1:n
x = split(t,[":" "."]);
x = double(x);
a = x(:,1);
b = x(:,2);
c = x(:,3);
d = x(:,4);
end
fprintf('My Solution: %f\n',toc);