Btukfyl

I am using pgfplotstableset and longtable to read data from a file and format it into a table composed of several subtables. I have managed to create the table and to include a caption over it. However, I would also like to include a subcaption over each one of the subtables and I have not been able to do it.

The desired output should look like:

I have created the table above with caption*. However, I would prefer to use subcaption to maintain the consistency of my references. Below, I include the minimal code, which I have used to create the table above. I have tried replacing caption* with subcaption and I get the following error:

! Package caption Error: subcaption outside float.

Minimal code.
article.tex:

documentclass{article} 

usepackage{conf-simple}

begin{document}

includetable{data/minimal-data.dat}{Minimal data}{minimal-data}

end{document}

conf-simple.sty:

ProvidesPackage{conf-simple}

usepackage{subcaption}

usepackage{pgfplotstable}

usepackage{longtable}

usepackage{booktabs}



pgfplotstableset{

begin table=begin{longtable},

create on use/double/.style={create col/expr={thisrowno{1}*2}},

end table=end{longtable},

}



newcommand{includetable}[3]{



noindentbegin{minipage}{textwidth}  

pgfplotstabletypeset[

col sep=space,

header=false, 

column type=r,   

columns={0,1,double},      % display specified columns

columns/0/.style={string type, column name =},

columns/1/.style={column name=small{Value}},

columns/double/.style={column name=small{Double}},

% requires booktabs to place horiz rules

every head row/.style={before row={caption{#2 label{table:#3}} \ caption*{(a) First subtable} \ toprule 

 multicolumn{3}{|c|}{Numbers} \ midrule}, after row=midrule},

every last row/.style={after row=bottomrule},

every first column/.style={column type/.add={|}{}},

every column/.style={column type/.add={}{|}},

]{#1}



end{minipage}



noindentbegin{minipage}{textwidth}

pgfplotstabletypeset[col sep=space,

header=false,    

columns={0,1},      % display specified columns

columns/0/.style={string type,column name=},

columns/1/.style={column name=small{Value}},

% requires booktabs to place horiz rules

every head row/.style={before row={caption*{(b) Second subtable} \ toprule  

   multicolumn{2}{|c|}{Numbers} \ midrule }, after row=midrule}, 

every last row/.style={after row=bottomrule},

every first column/.style={column type/.add={|}{}},

every column/.style={column type/.add={}{|}},

]{#1}

end{minipage}



}



end{document}

Minimal data file:

One 1

Two 2

Three 3

As far as I understand, the problem is related to longtable not accepting subcaptions but I do not know how to build my table in a different way.

I have found related questions like this and this but they do not solve my issue.

Only use fixsubtable inside a minipage or other group.

documentclass{article}

usepackage{subcaption}

usepackage{longtable}



makeatletter

newcommand{fixsubtable}{letcaption=caption@caption

  def@captype{table}}

makeatother



begin{document}



begin{longtable}{@{}c@{}}

caption{No Data}

endhead

endfoot

begin{minipage}{textwidth}

fixsubtable

subcaption{First subtable}

centering

rule{0.25textwidth}{0.25textwidth}

end{minipage}\

end{longtable}



end{document}