Cfrgtkky

I am trying to create a visual for a linear transformation done by matrices. Here is an example of what I am shooting for:

I would like to have the original gridlines in place, but like faded out a bit, and the newly transformed gridlines more visible.

Here is my attempt using pgftransformcm:

documentclass{article}

usepackage{amsmath}

usepackage{xcolor}

usepackage{pgfplots}



begin{document}



begin{tikzpicture}[scale=1,line width=1pt]



begin{axis}[

color= black, 

thick,

xmin=-3.9, 

xmax=3.9, 

ymin=-3.9, 

ymax=3.9, 

axis equal image, 

axis lines=middle, 

font=scriptsize,

xtick distance=1,

ytick distance=1,

inner axis line style={stealth-stealth},

xlabel = {},

ylabel = {},

grid=major,

ticks=none

]



end{axis}



begin{axis}[

color= blue, 

thick,

xmin=-3.9, 

xmax=3.9, 

ymin=-3.9, 

ymax=3.9, 

axis equal image, 

axis lines=middle, 

font=scriptsize,

xtick distance=1,

ytick distance=1,

inner axis line style={stealth-stealth},

xlabel = {},

ylabel = {},

grid=major,

grid style={blue!50},

ticks=none

]



pgftransformcm{1}{1}{0}{1}{pgfpoint{0}{0}};



end{axis}



end{tikzpicture}



end{document}

And here is my result:

I am very unfamiliar with pgftransformcm, and so I am sure there is an easy fix to this that I am not seeing. It seems that for some reason the shifted gridlines are no longer centered at the origin when I use this command, which I do not want.

I also have used the axis environment only because I am used to using it for making graphs with pgfplots, and for me, having a coordinate system is much more desirable than using arbitrary points that you do without the environment (so for example, I would be able to draw a vector to the point (2,2) and know exactly where it would land). But that is just my personal preference, and if no solution is possible without removing the environment, then so be it.

I apologize if this seems like a long-winded question, but I have no idea how to approach this question. Any help would be appreciated!

I take back what I wrote in my comment. pgftransformcm is actually the easier option here. This code provides two ways to achieve the result.

documentclass[border=3.14mm,tikz]{standalone}

begin{document}

begin{tikzpicture}

 fill[clip] (-8,-5) rectangle (8,5);

 draw[white] (-8,-5) grid (8,5);

 begin{scope}[x={(3,-2)},y={(2/3,7/3)}]

  foreach X in {-2,...,2}

  {draw[red!30] (X,-5) -- ++ (0,10);}

  foreach Y in {-4,...,4}

  {draw[blue!30] (-3,Y) -- ++ (6,0);}

  draw[yellow,thick,-latex] (0,0) -- (1,0) node[above right]{$x'$};

  draw[orange,thick,-latex] (0,0) -- (0,1) node[above left]{$y'$};

 end{scope}

end{tikzpicture}



begin{tikzpicture}

 fill[clip] (-8,-5) rectangle (8,5);

 draw[white] (-8,-5) grid (8,5);

 begin{scope}

  pgftransformcm{3}{-2}{2}{1}{pgfpoint{0cm}{0cm}}

  foreach X in {-2,...,2}

  {draw[red!30] (X,-5) -- ++ (0,10);}

  foreach Y in {-4,...,4}

  {draw[blue!30] (-3,Y) -- ++ (6,0);}

  draw[yellow,thick,-latex] (0,0) -- (1,0) node[above right]{$x'$};

  draw[orange,thick,-latex] (0,0) -- (0,1) node[above left]{$y'$};

 end{scope}

end{tikzpicture}

end{document}