Read a string with numbers and scientific notations

Dear All,

I am trying to read a text file looks like this:

# Counters
sec=60, Monitor=8.66289e+06, bstop=818664, I0=829726, I1=0, ch5=0, ch6=0, ch7=0.

I would like to read the Monitor value (8.66289e+06). I was using

k=sprintf('txt_files/MnO2_20170512_05120943_%04d.txt',i);    
filetext=fileread(k);
numbers = str2double(regexp(filetext, '(?<=Monitor=[^0-9]*)[0-9]*\.?[0-9]+', 'match'));

In this way I can get the number "8.66289". But today I would like to include the scientific notation as well. So my output will be "8.66289e+06". I am not really sure how to proceed with this even though I searched in the forum.

I tried

numbers3 = regexp(filetext, '(?<== )((\d|(+)|(\.)|(e))+','match');

and

numbers3=sscanf(sprintf('%s ',numbers3{:}),'%g')

But looks like something was not right in my code.

Thank you for help!

Answer 1

[Walter Roberson]

S = 'sec=60, Monitor=8.66289e+06, bstop=818664, I0=829726, I1=0, ch5=0, ch6=0, ch7=0.';
result = regexp(S, '(?<name>\w+)=(?<value>[^,]+)', 'names');

>> result(2)
ans = 
  struct with fields:

       name: 'Monitor'
      value: '8.66289e+06'

[BRC]

Thank you very much for answering my question! It worked out perfectly. A follow-up question though...could you let me know how to pull out the 8.66289e+06 and save it to an array? I have 1000 files but I am not familiar with structure files. Thanks!!

[BRC]

I tried

numbers= regexp(filetext, '(?<name>\w+)=(?<value>[^,]+)', 'names');
a=numbers(2);
c = struct2cell(a);
m(i)=c(2)

but the error message was

The following error occurred converting from cell
to double:
Error using double
Conversion to double from cell is not possible.

[Walter Roberson]

all_values_as_numeric = str2double( {result.value} );

Note: if you can count on the order being the same each time, then

S = 'sec=60, Monitor=8.66289e+06, bstop=818664, I0=829726, I1=0, ch5=0, ch6=0, ch7=0.';
result = regexp(S, '(?<==)([^,]+)', 'match');
all_values_as_numeric = str2double(result);