It takes me much effort to install pstricks.
I am using Mac OS, and I don't want the full version of MacTex which takes too much space to store. I choose to use texlive, unfortunately texlive is not updated anymore,
which means using "tlmgr install pstricks" will not succeed.
The way to install pstricks is just to install it manually.
1. download all needed files
2. put files into correct folder
ALL files can be found here, http://tug.org/PSTricks/main.cgi?file=packages
[1]. dvips files "2015basic/texmf-dist/dvips/pstricks/"
pst-3d.pro pst-math.pro
pstricks-add.pro
pst-algparser.pro pst-node.pro
pstricks.pro
pst-dots.pro pst-tools.pro
[2]. tex files "2015basic/texmf-dist/tex/latex/pstricks/"
multido.tex pst-grad.tex
pst-plot.tex
pst-3d.tex pst-key.tex
pst-tools.tex
pst-arrow.tex pst-math.tex
pstricks-add.tex
pst-fp.tex pst-node.tex
pstricks.tex
[3]. sty files "2015basic/texmf-dist/tex/latex/pstricks/"
multido.sty pst-key.sty
pst-tools.sty
pst-3d.sty pst-math.sty
pstcol.sty
pst-all.sty pst-node.sty
pstricks-add.sty
pst-arrow.sty pst-grad.sty
pst-plot.sty pstricks.sty
When compile your tex file, try "latex => dvips => ps2pdf"
latex slides.tex
dvips slides.dvi
ps2pdf slides.ps
That's it.