Confused with different behaviors of nodes and literal points when using origin option

Question

I have not found a document explaining my problem below. In my understanding, if \pnode(1,1){A} then \pscircle[origin={A}](A){1} must be identical to

• \pscircle[origin={1,1}](A){1}
• \pscircle[origin={A}](1,1){1}
• \pscircle[origin={1,1}](1,1){1}

However, I got the following result that is different from my mental model above. How does PSTricks make assumption when handling nodes and literal points?

\documentclass[border=12pt]{standalone}
\usepackage{pst-node}
\psset{linecolor=red}

\def\xxx{\hspace{5mm}}

\begin{document}

\begin{pspicture}[showgrid=top](3,3)
\pnode(1,1){A}
\pscircle[origin={A}](A){1}
\end{pspicture}\xxx

\begin{pspicture}[showgrid=top](3,3)
\pnode(1,1){A}
\pscircle[origin={1,1}](A){1}
\end{pspicture}\xxx

\begin{pspicture}[showgrid=top](3,3)
\pnode(1,1){A}
\pscircle[origin={A}](1,1){1}
\end{pspicture}\xxx

\begin{pspicture}[showgrid=top](3,3)
\pscircle[origin={1,1}](1,1){1}
\end{pspicture}

\end{document}

Answer 1

origin={x,y} is the equivalent of shift={(x,y)} supplied to a scope in TikZ or a local shift to the coordinate system:

\begin{tikzpicture}
\node (o) {O};
\begin{scope}[shift={(2,2)}]
\node (a) at (o) {A};
\end{scope}
\end{tikzpicture}

In this one it doesn't matter if the coordinate system is shifted or not. The command says put this at node named (o). So no shift is applied. Same happens with the origin={A}. The code says shift the coordinate system but then the same code says put it where A is so the net effect is moving the center of the circle to {A}.

\documentclass[border=12pt]{standalone}
\usepackage{pst-node}
\psset{linecolor=red}


\begin{document}

\begin{pspicture}[showgrid=top](5,3)
\pnode(2,1){A}
\pscircle[origin={1,1}](A){1} %<---- A is a fixed point, no effect via origin 
\psdiamond[framearc=.3,fillstyle=solid,      %<---- No fixed point, coords of A are 
fillcolor=lightgray,origin={A}](3,0)(1.5,1)  % added to the coordinate system
\pscircle[origin={1,1}](0,0){1}              % Same here
\end{pspicture}

\end{document}