How to read the PRE html tags and replace some white spaces

I read data from html file and delimmited by the following tags

<pre>
  12.0  29132  -60.3  -91.4      1   0.01    260         753.2  753.3  753.2
  10.0  30260  -57.9             1   0.01    260     58  802.4  802.5  802.4
  9.8   30387  -57.7  -89.7      1   0.01    261     61  807.8  807.9  807.8
  6.0   33631  -40.4  -77.4      1   0.17    260     88 1004.0 1006.5 1004.1
  5.9  33746  -40.3  -77.3       1   0.17               1009.2 1011.8 1009.3

   </pre>

    by the code:

t = regexp(html, '<PRE[^>]*>(.*?)</PRE>', 'tokens');

where t is a cell of char

Well, now I am trying to replace blank space with NaN to obtain:

    12.0  29132  -60.3  -91.4      1   0.01    260    Nan  753.2  753.3  753.2
    10.0  30260  -57.9   Nan     1   0.01    260     58  802.4  802.5  802.4
     9.8  30387  -57.7  -89.7      1   0.01    261     61  807.8  807.9  807.8
     6.0  33631  -40.4  -77.4      1   0.17    260     88 1004.0 1006.5 1004.1
     5.9  33746  -40.3  -77.3      1   0.17    NaN    NaN 1009.2 1011.8 1009.3

In this data set the columns are not always delimited by the same space and I do not know the lenght of the white spaces.

For example: in the last one line of my frist one data set there are two "empty places" that I would replace with 'NaN'. The position of all elements can't be changed (textscan function is dangerous I think)

Do you have any suggestion? Maybe I should to read the PRE tags by another way?

Thank you

Answer 1

[Cedric]

I've got to run, but here is one way (I'll come back later to discuss further if needed).

EDIT: the first solution could not work, I will update it as soon as I have more information.

[Stefano]

Yes, I have case with consecutive missing values in the same line, you can view in the last one line of my data set above.

[Stefano]

I would like to point out that I have already a cell that contains the data is: t = regexp(html, '<PRE[^>]*>(.*?)</PRE>', 'tokens'); It would be ideal to start out from here

[Cedric]

Ok, I have a little more time now. Can any column be missing or is there one or more which is/are always present? Also, what is the range (or the range of the width) of the numbers in each column? Finally, could you attach a sample, so I have the exact content, because the forum alters a bit the content.

[Stefano]

Thank you for your interest. The first two columns are always present. I can't know the range of the numbers but I could only estimate it. I attached a .txt file with another situation. Whereas that I have a file of data, I could to solve reading the .txt file for replacing the blank space? It could be another way...but I haven't idea how to.

[Cedric]

Ok, this is a table with 7 characters fixed column width. So you can process it as follows

 regexprep( content, ' {7}', '    NaN' )

where content is the token that is outputted by you first call to REGEXP. If you have more than 7 white spaces at the beginning of each line, e.g. because of HTML indentation, we can refine the pattern to exclude them. Just let me know.

[Stefano]

Ok, thank you! Good job! It's a perfect solution for my data. Answer accepted :)