Cfrgtkky

MWE

% stand-alone file to test writing a table in pgfplotstable

documentclass{book}

usepackage{booktabs,multirow} % required

usepackage{pgfplotstable}

pgfplotsset{compat=1.16}

begin{document}

%renewcommand{arraystretch}{1.2}

pgfplotstabletypeset

 [

  after row = vspace{0.8mm},

  every head row/.style =

  {

    before row = toprule,

    after row = midrule,

  },

  every last row/.style =

  {

    after row = bottomrule,

  },

  columns/x/.style =

  {

    column type = r,

    column name = $x$,

    frac,

  },

  columns/y/.style = 

  {

    column type = r,

    column name = ${y=frac{2}{x}}$,

    frac,

  },

 ]

 {

     x    y

     -4   -0.5         % vertical space not added after this row

     -3   -0.66666666  % vert space added below here

     -2   -1

     -1   -2

     -0.5 -4

      0.5  4

      1    2

      2    1

      3    0.66666666

      4    0.5

 } % pgfplotstabletypeset{} END

end{document}

To display columns of fractions (with pgfplotstable, booktabs and multirows), I need to add vertical space between the rows so the fraction of the current row does not step on the fraction of the previous row. As shown in the MWE, I added

after row = {vspace{0.8mm}},

to the options for pgfplotstabletypeset, but it compiled by adding space to every row after row 1, not between rows 0 and 1. See image.

I added the usual arraystretch command (commented out in MWE) prior to pgfplotstabletypeset, but it is outside my block, and since I have dozens of tables in this document, not all need to have the array stretch applied. Yes, I could put braces around the source text, but I hope there is something cleaner to add to the options that I missed.

Why is the space not added between rows 0 and 1?

pgfplotstable allows you to specify the code for fractions via frac TeX. This can be used to add more vertical space where fractions appear e.g. by adding a vertical phantom.

documentclass{book}

usepackage{booktabs,multirow} % required

usepackage{pgfplotstable}

pgfplotsset{compat=1.16}

begin{document}

%renewcommand{arraystretch}{1.2}

pgfplotstabletypeset

 [

  after row ={[0.3ex]}, %<use this instead of vspace

  frac TeX=vphantom{displaystylefrac{1}{2}}frac,

  every head row/.style =

  {

    before row = toprule,

    after row = midrule,

  },

  every last row/.style =

  {

    after row = bottomrule,

  },

  columns/x/.style =

  {

    column type = r,

    column name = $x$,

    frac,

  },

  columns/y/.style = 

  {

    column type = r,

    column name = ${y=frac{2}{x}}$,

    frac,

  },

 ]

 {

     x  y

     -4 -0.5

     -3 -0.66666666 

     -2 -1

     -1 -2

     -0.5   -4

      0.5   4

      1 2

      2 1

      3 0.66666666

      4 0.5

 } % pgfplotstabletypeset{} END

end{document}