[Tex/LaTex] Draw a 2D functions in tikz

3dpgfplotstikz-3dplottikz-pgf

I want to be able to plot in a 3D environment any type of function of two variables z = f(x,y), where x and y are specified within a given range. For instance plot f(x,y) = x^2 + y^2 where x in [-2,2] and y in [-2,2] as a "wireframe" surface plot. I want this plot to go on the rectangle (defined in the same coordinate system) that I have drawn, without the axis labels. How can this be done

\documentclass[border=10pt,varwidth]{standalone}
\usepackage{tikz,tikz-3dplot}
\usepackage{pgfplots}

\pgfplotsset{
    every axis/.append style = {thick},tick style = {thick,black},
    %
    % #1 = x, y, or z
    % #2 = the shift value
    /tikz/normal shift/.code 2 args = {%
        \pgftransformshift{%
            \pgfpointscale{#2}{\pgfplotspointouternormalvectorofticklabelaxis{#1}}%
        }%
    },%
    %
    range3frame/.style = {
        tick align        = outside,
        scaled ticks      = false,
        enlargelimits     = false,
        ticklabel shift   = {10pt},
        axis lines*       = left,
        line cap          = round,
        clip              = false,
        xtick style       = {normal shift={x}{10pt}},
        ytick style       = {normal shift={y}{10pt}},
        ztick style       = {normal shift={z}{10pt}},
        x axis line style = {normal shift={x}{10pt}},
        y axis line style = {normal shift={y}{10pt}},
        z axis line style = {normal shift={z}{10pt}},
    }
}



\begin{document}



% ----- First plot    
\tdplotsetmaincoords{70}{155}
\begin{tikzpicture} [scale=3, tdplot_main_coords, axis/.style={->,blue,thick},
vector/.style={-stealth,black,very thick},
vector guide/.style={dotted,black,thick},
]

%standard tikz coordinate definition using x, y, z coords
\coordinate (O) at (0,-0.5,0);

%tikz-3dplot coordinate definition using r, theta, phi coords
\pgfmathsetmacro{\ax}{1}
\pgfmathsetmacro{\ay}{-1}
\pgfmathsetmacro{\az}{0.5}

\coordinate (P) at (\ax,\ay,\az){};

%draw axes
    \draw[axis] (0,-0.5,0) -- (2,-0.5,0) node[anchor=north east]{$y$};   % x-axis becomes y axis
    \draw[axis] (0,-0.5,0) -- (0,-2,0) node[anchor=south]{$x$}; %minius y-axis becomes positive x axis
    \draw[axis] (0,-0.5,0) -- (0,-0.5,2) node[anchor=south]{$z$};





\draw[thick,tdplot_main_coords] (1.5,0.5,0)-- (1.5,-0.5,0) -- (-1.5,-0.5,0)--(-1.5,0.5,0)--cycle;




\begin{axis}[range3frame, view={55}{45}]
    \addplot3[surf, colormap/hot2, samples=41, domain=0:2] {0.1*(x^2+y^2)};
\end{axis}

\end{tikzpicture}

\end{document}

Best Answer

How about this

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}

\begin{document}

\begin{tikzpicture}
    \begin{axis}[xmin=-2,xmax=2,ymin=-2,ymax=2,axis lines=none]
        \addplot3[mesh] {x^2+y^2};
    \end{axis}
\end{tikzpicture}


\end{document}

It will need some fine tuning, but it basically works.

I slightly changed it by adding axis lines=none in order to hide the axis lines. It is still a bit ugly, but I don't use pgfplots regularly, so I am not very used to the styling possibilities it offers.

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