filtragem de dados condicionais pgfplots

Question

Estou me perguntando se existe uma maneira de filtrar pontos de dados nos argumentos \addplot. Tenho um conjunto de dados (veja MWE abaixo) cujos valores correspondem a uma das três condições (C). Eu gostaria de poder ler o conjunto de dados completo usando pgfplots com três comandos \addplot separados (um para cada valor de C), cada um dos quais filtra as linhas que não correspondem a esse valor C, plotando cada condição com marcadores separados, etc. Isso é possível ou não?

Eu olhei para as opções skip coords between indexe x filter/ filter point, mas como estes são argumentos para a axisfunção (e, portanto, alteram todo o gráfico), eles não parecem fazer o que eu quero.

Aqui está um MWE que mostra o que quero alcançar:

\documentclass{standalone}

\usepackage{pgfplots}

\usepackage{filecontents}

\begin{filecontents}
C   P1      P2      P3  sigP3
1   1.12E-4 0.06189 0.1865  0.0080
1   6.03E-3 0.00000 0.2517  0.0046
1   2.64E-2 0.00000 0.2247  0.0165
2   6.49E-5 0.00000 0.1906  0.0043
2   1.27E-5 0.00296 0.2120  0.0039
2   3.34E-4 0.00865 0.1709  0.0050
3   1.59E-2 0.01857 0.1596  0.0216
3   7.10E-4 0.01857 0.2547  0.0316
3   3.23E-5 0.00526 0.1557  0.0051
3   2.33E-4 0.01857 0.2008  0.0136
3   5.80E-4 0.01857 0.2389  0.0172
\end{filecontents}

\begin{document}

\begin{tikzpicture}
  \pgfplotsset{legend cell align=right,legend style={font=\footnotesize,legend pos=outer north east}};
  \begin{semilogxaxis}[
      enlargelimits=false,axis on top,
      width=12cm,height=8cm,
      xlabel={$\Pi_1$},
      ylabel={$\Pi_3$},
      ymin=0.1,ymax=0.35,
      xmin=1E-5,xmax=1E-1,
    ]

    %% PLOT ONLY IF C = 1
    \addplot+[only marks,error bars/.cd,y dir=both,y explicit] coordinates {
      (1.12E-4,0.1865) +- (0,0.0080)
      (6.03E-3,0.2517) +- (0,0.0046)
      (2.64E-2,0.2247) +- (0,0.0165)
    };
    \addlegendentry{Cond. 1}

    %% PLOT ONLY IF C = 2
    \addplot+[only marks,error bars/.cd,y dir=both,y explicit] coordinates {
      (6.49E-5,0.1906) +- (0,0.0043)
      (1.27E-5,0.2120) +- (0,0.0039)
      (3.34E-4,0.1709) +- (0,0.0050)
    };
    \addlegendentry{Cond. 2}

    %% PLOT ONLY IF C = 3
    \addplot+[only marks,error bars/.cd,y dir=both,y explicit] coordinates {
      (1.59E-2,0.1596) +- (0,0.0216)
      (7.10E-4,0.2547) +- (0,0.0316)
      (3.23E-5,0.1557) +- (0,0.0051)
      (2.33E-4,0.2008) +- (0,0.0136)
      (5.80E-4,0.2389) +- (0,0.0172)
    };  
    \addlegendentry{Cond. 3}

  \end{semilogxaxis}
\end{tikzpicture}

\end{document}

Answer 1

Você pode usar restrict expr to domain:

  \begin{filecontents*}{mydata.dat}
  C   P1      P2      P3  sigP3
  1   1.12E-4 0.06189 0.1865  0.0080
  1   6.03E-3 0.00000 0.2517  0.0046
  1   2.64E-2 0.00000 0.2247  0.0165
  2   6.49E-5 0.00000 0.1906  0.0043
  2   1.27E-5 0.00296 0.2120  0.0039
  2   3.34E-4 0.00865 0.1709  0.0050
  3   1.59E-2 0.01857 0.1596  0.0216
  3   7.10E-4 0.01857 0.2547  0.0316
  3   3.23E-5 0.00526 0.1557  0.0051
  3   2.33E-4 0.01857 0.2008  0.0136
  3   5.80E-4 0.01857 0.2389  0.0172
  \end{filecontents*}

  \documentclass[margin=10pt]{standalone}
  \usepackage{pgfplots}
  \pgfplotsset{compat=1.12}
  \begin{document}
  \begin{tikzpicture}
    \pgfplotsset{
      legend cell align=right,
      legend style={font=\footnotesize,legend pos=outer north east}}
    \begin{semilogxaxis}[
        enlargelimits=false,axis on top,
        width=12cm,height=8cm,
        xlabel={$\Pi_1$},
        ylabel={$\Pi_3$},
        ymin=0.1,ymax=0.35,
        xmin=1E-5,xmax=1E-1,
        log basis x=10,
      ]
      \addplot+[only marks,error bars/.cd,y dir=both,y explicit]
        table[x=P1,y=P3,y error=sigP3,
        restrict expr to domain={\thisrow{C}}{1:1}
        ]{mydata.dat}; 
      \addlegendentry{Cond. 1}
      \addplot+[only marks,error bars/.cd,y dir=both,y explicit]
        table[x=P1,y=P3,y error=sigP3,
        restrict expr to domain={\thisrow{C}}{2:2}
        ]{mydata.dat}; 
      \addlegendentry{Cond. 2}
      \addplot+[only marks,error bars/.cd,y dir=both,y explicit]
        table[x=P1,y=P3,y error=sigP3,
        restrict expr to domain={\thisrow{C}}{3:3}
        ]{mydata.dat}; 
      \addlegendentry{Cond. 3}
    \end{semilogxaxis}
  \end{tikzpicture}
  \end{document}

Ou com\pgfplotsinvokeforeach

  \documentclass[margin=10pt]{standalone}
  \usepackage{pgfplots}
  \pgfplotsset{compat=1.12}
  \begin{document}
  \begin{tikzpicture}
    \pgfplotsset{
      legend cell align=right,
      legend style={font=\footnotesize,legend pos=outer north east}}
    \begin{semilogxaxis}[
        enlargelimits=false,axis on top,
        width=12cm,height=8cm,
        xlabel={$\Pi_1$},
        ylabel={$\Pi_3$},
        ymin=0.1,ymax=0.35,
        xmin=1E-5,xmax=1E-1,
        log basis x=10,
      ]
    \pgfplotsinvokeforeach{1,2,3}{ 
        \addplot+[only marks,error bars/.cd,y dir=both,y explicit]
          table[x=P1,y=P3,y error=sigP3,
          restrict expr to domain={\thisrow{C}}{#1:#1}
          ]{mydata.dat}; 
        \addlegendentry{Cond. #1};
     } 
    \end{semilogxaxis}
  \end{tikzpicture}
  \end{document}