Using regular expression to extract numeric data from text file

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Søren Holm-Petersen 2020-3-3

0
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https://ww2.mathworks.cn/matlabcentral/answers/508815-using-regular-expression-to-extract-numeric-data-from-text-file

评论： Søren Holm-Petersen 2020-3-4

采纳的回答： Stephen23

triangle_positions.txt

在 MATLAB Online 中打开

Hi, I have a text file containing a bunch of lines with the following format:

"Triangle(Vector3D(-0.125, -0.375, 0), Vector3D(0.125, -0.375, 0.166396), Vector3D(0.125, -0.375, 0))"

I would like to extract the numeric values contained within the parentheses.

Right now I am attempting to make a matrix Mx9, where M is the number of lines in the text file, and the 9 comes from the 3 elements of the three vectors. I try doing this using a regular expression and capture groups:

string = fileread('triangle_positions.txt')
expression = '(-?\d+\.?\d*),\s(-?\d+\.?\d*),\s(-?\d+\.?\d*)'
tokens = regexp(string, expression, 'tokens');

The result is a "cell" containing the values as strings. For a single line I get a "1x3 cell" where each cell contains the coordinates of the vector as strings.

How would you convert this into a regular matlab matrix?

Thanks in advance

Søren