# Draw bivariate normal distribution in x-z plane

In draw-a-bivariate-normal-distribution-in-tikz, the bivariate normal distribution was plotted on the x-y plane. Is it possible to plot this on the x-z plane/y-z plane?

Sure. You can use the syntax \addplot3 ({x expr}, {y expr}, {z expr}); for this:

\documentclass[border=5mm]{standalone}

\usepackage{pgfplots}

\begin{document}

\pgfplotsset{
colormap={whitered}{color(0cm)=(white); color(1cm)=(orange!75!red)}
}

\begin{tikzpicture}[
declare function={mu1=1;},
declare function={mu2=2;},
declare function={sigma1=0.5;},
declare function={sigma2=1;},
declare function={normal(\m,\s)=1/(2*\s*sqrt(pi))*exp(-(x-\m)^2/(2*\s^2));},
declare function={bivar(\ma,\sa,\mb,\sb)=
1/(2*pi*\sa*\sb) * exp(-((x-\ma)^2/\sa^2 + (y-\mb)^2/\sb^2))/2;}]
\begin{axis}[
colormap name=whitered,
width=15cm,
view={45}{35},
enlargelimits=false,
grid=major,
domain=-1:4,
y domain=-1:4,
samples=26,
z buffer=sort,
unit vector ratio=10 1 1,
xmin=0, xmax=0.2,
ymin=-1, ymax=4
]