extract data from string

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Trae
Trae on 30 Apr 2022
Edited: dpb on 30 Apr 2022
'%R1P,0,0:0,0.452743429299473,0.000005129603507,0.0000002,0,0.000002,0,0,25899036'
How could I extract the 4th,5th,10th and 11th data from this string to a matrix?

Accepted Answer

Voss
Voss on 30 Apr 2022
Maybe something like this:
str = '%R1P,0,0:0,0.452743429299473,0.000005129603507,0.0000002,0,0.000002,0,0,25899036';
% split str on commas into a cell array:
c = strsplit(str,',')
c = 1×11 cell array
{'%R1P'} {'0'} {'0:0'} {'0.452743429299473'} {'0.000005129603507'} {'0.0000002'} {'0'} {'0.000002'} {'0'} {'0'} {'25899036'}
% convert elements [4 5 10 11] to numeric:
m = str2double(c([4 5 10 11]));
% display elements of m separately:
format long
for ii = 1:numel(m)
disp(m(ii));
end
0.452743429299473 5.129603507000000e-06 0 25899036
  9 Comments
Trae
Trae on 30 Apr 2022
hw to chnge the headings
Voss
Voss on 30 Apr 2022
One way is to type them out:
headings = {'No' 'whatever' 'they' 'should' 'be'};

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More Answers (1)

dpb
dpb on 30 Apr 2022
Edited: dpb on 30 Apr 2022
The dead-ahead approach...
>> tok=split(s,',');
>> str2double(tok([4:5 10:11]))
ans =
0.45274
5.1296e-06
0
2.5899e+07
>>
A different solution to the second Q? would be more like
VARS=[4 5 10 11]; % the wanted variables
tok=strsplit(s,',');
vNames=compose('Var%02d',1:numel(VARS));
tData=array2table(str2double(tok(VARS)),'VariableNames',vNames);
The results of the last plus how to change names example are:
>> tData=array2table(str2double(tok(VARS)),'VariableNames',vNames)
tData =
1×4 table
Var01 Var02 Var03 Var04
_______ __________ _____ __________
0.45274 5.1296e-06 0 2.5899e+07
>> tData.Properties.VariableNames(2)={'MyNewName'}
tData =
1×4 table
Var01 MyNewName Var03 Var04
_______ __________ _____ __________
0.45274 5.1296e-06 0 2.5899e+07
>>
This takes advantage that the table has the facility for variable names built into the class as an integral part of the class instead of confusing data and the title into a single variable from which it always has to be extracted in order to use the data in the array....and, it allows the data to be of any type whereas adding a variable name for a numeric array requires that the whole array then be a cell array to hold the disparate data types.

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