[RR Python] Matplotlib with VNC

while using VNC with matplotlib, I found that there is error "_tkinter.tclerror couldn't connect to display 1.0"

the solution is here 

quote as below

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Write these few lines to etc/sudoers*:

Defaults    env_reset
Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
Defaults    env_keep += "DISPLAY"
Defaults    env_keep += "XAUTHORITY"

And these few lines to ~/.bashrc:

if [ -z "$XAUTHORITY" ]; then
    if [ -e $HOME/.Xauthority ]; then
        export XAUTHORITY=$HOME/.Xauthority;
    fi;
fi

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