siunitx alignment in tables with both text and math

Question

I'm trying to make a table in which the last column has mixed input of text and numbers in the same cell, and I want to align them at the decimal point, irrespective of the lenght of the preceeding text (though is usually a symbol like <, >, etc.). The problem is that the numbers overlap the text.

MWE:

\documentclass{article}
\usepackage{booktabs}
\usepackage{siunitx}
\begin{document}
\begin{table}
\begin{tabular}{@{}l S[table-format=1.4] @{}}
& {p} \\
\midrule
Model & {\textless{}} 0,0001 \\
\hspace{0.5cm}A & {\textless{}} 0,0001 \\
\hspace{0.5cm}B & 0,2980 \\
\hspace{0.5cm}C & 0,0007 \\
\end{tabular}
\end{table} 
\end{document}

results in:

If I use:

\documentclass{article}
\usepackage{booktabs}
\usepackage{siunitx}
\begin{document}
\begin{table}
\begin{tabular}{@{}l S[table-format=1.4] @{}}
& {p} \\
\midrule
Model & {text} {0.0001} \\
\hspace{0.5cm}A & {\textless{}} {0.0001} \\
\hspace{0.5cm}B & 0.2980 \\
\hspace{0.5cm}C & 0.0007 \\
\end{tabular}
\end{table} 
\end{document}

I get:

with no space between "text" and "0.0001", and the numbers not aligned at the decimal point.

If I try aligning the numbers to the right and centering the title:

\documentclass{article}
\usepackage{booktabs}
\usepackage{siunitx}
\begin{document}
\begin{table}
\begin{tabular}{@{}l r@{}}
& \multicolumn{1}{c}{p} \\
\midrule
Model & {\textless{}} {0.0001} \\
\hspace{0.5cm}A & {\textless{}} {0.0001} \\
\hspace{0.5cm}B & 0.2980 \\
\hspace{0.5cm}C & 0.0007 \\
\end{tabular}
\end{table} 
\end{document}

the result is:

which is still wrong, as the title is not centered in the column (it's more to the left side than it should be).

I also tried declaring mode=text in the preamble for siunitx, but still couldn't get the result I want.

Is there any way to get a single column with the header centered with the text below, and cells with some text followed by a space and then numbers aligned at the decimal point? Something closer to this mock-up:

I'm trying to avoid manual adjustments like \hspace{} or the like. Thanks.

EDIT OK, thanks to @Mico's code I got closer to what I want. I've added a few digits at both sides of the decimal marker to check the alignment of the text before and after the numerals. MWE:

\documentclass{article}
\usepackage{booktabs}
\usepackage{siunitx}
\sisetup{
  output-decimal-marker = {,},
  table-number-alignment = center,
  table-align-comparator = false,
  table-align-text-pre = false,
  table-align-text-post = false,
  table-space-text-pre = \, ,
}
\begin{document}

\begin{tabular}{c S[table-format=2.8, table-comparator=true]}
  & {Value} \\
  \midrule
  Model & <9,0001 \\
  A     & >90,001 \\
  B     &  0,29801111 \\
  C     & \sim 0,0007 \\
  D     & \approx 1,030356{\textsuperscript{a}}
\end{tabular}

\end{document}

gives:

Now I only need to find a way to control the spacing between the pre- and post- text. I'd like a small space (like \,) between the comparator symbol and the numeral. The idea is to define this globally, to avoid having to define something like \newcommand{\ssim}{\sim\,} for every symbol (<, >, ~, ±, etc.). Thanks.

Answer 1

You could add the options table-align-text-pre = false and table-space-text-pre = < to the specification of the S column.

\documentclass{article}
\usepackage{booktabs}
\usepackage[output-decimal-marker={,}]{siunitx}
\begin{document}
\begin{tabular}{@{} c S[table-format=1.4,
                        table-align-text-pre = false,
                        table-space-text-pre = <] @{}}
  & $p$ \\
  \midrule
  Model & <0,0001 \\
  A     & <0,0001 \\
  B     &  0,2980 \\
  C     &  0,0007
\end{tabular}
\end{document}

Answer 2

Have you tried the option table-alignment-mode=marker.

Like so:

\documentclass{article}
\usepackage{booktabs}
\usepackage{siunitx}
\begin{document}
    \begin{tabular}{@{}c S[table-format=1.4,table-alignment-mode = marker] @{}}
        & {p} \\
        \midrule
        Model & {text} 0.0001 \\
        A & < 0.0001 \\
        B & 0.2980 \\
        C & 0.0007 \\
    \end{tabular}
\end{document}

Looks like:

Note that actual text requires {}, while math operators such as > or < do not, because siunitx knows how to interpret them.

EDIT: If you want the decimal point to be a comma like in your initial example feel free to add an additional output-decimal-marker={,}

Answer 3

If anyone is interested, the answer is to add the comparator to the preamble:

\usepackage{siunitx}
\sisetup{
  table-align-comparator=false,
  table-align-text-pre=false,
  input-comparators={\textless}
}

and then add a space after the comparator in the table:

\textless{ } 0,0001