# Extract only numbers from a text file with Matlab

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K. Taieb on 29 Jun 2020
Commented: K. Taieb on 1 Jul 2020
In my txt file I have many lines with the following form:
I want to extract only the numbers that are between “ ” and after and only after x= and y=.
<Point x="-1.16804" y="-0.18000" z="1.60000" i="0.000000" j="0.000000" k="1.000000" u="1.000000" v="0.000000" w="0.000000" />
<Point x="-6.54428" y="-0.12000" z="1.60000" i="0.000000" j="0.000000" k="1.000000" u="1.000000" v="0.000000" w="0.000000" />
<Point x="-0.68936" y="-0.12000" z="1.60000" i="0.000000" j="0.000000" k="1.000000" u="1.000000" v="0.000000" w="0.000000" />
<Point x="-6.85390" y="-0.06000" z="1.60000" i="0.000000" j="0.000000" k="1.000000" u="1.000000" v="0.000000" w="0.000000" />
Can anyone help me?
Thank you.

Walter Roberson on 29 Jun 2020
I recommend using regexp with named tokens and the 'names' option. For example
parts = regexp(S, 'x="(?<x>[^"])"\s+y="(?<y>[^"])', 'names')
parts would then be a struct array of character vectors with fields x and y
x = str2double({parts.x} );
y = str2double({parts.y} );

K. Taieb on 30 Jun 2020
thank you
I did :
cell_str_2=strsplit(str,'\n');
parts = regexp(cell_str_2, 'x="(?<x>[^"])"\s+y="(?<y>[^"])', 'names');
x=str2double({parts.x});
y=str2double({parts.y});
I have the following error Walter Roberson on 30 Jun 2020
parts = regexp(str, 'x="(?<x>[^"]+)"\s+y="(?<y>[^"]+)', 'names');
x=str2double({parts.x});
y=str2double({parts.y});
K. Taieb on 1 Jul 2020
Great!
Thank you