Pretty-printing the LaTeX code

[mirkobunse]

The biggest advantage of PGFPlots over other plotting packages is that it enables users to alter the LaTeX code. I frequently fine-tune the size, colors, and other properties of a plot to the available space in a scientific paper or a slide set. Almost always, this fine-tuning happens long after the initial plot was generated in Julia.

This PR improves how the LaTeX code is formatted. Namely, the indentation, line breaks, and whitespaces are placed so that a human reader of the code can grasp more easily what is going on. This eases altering the code a lot.

Examples

The following examples are also presented in doc/PGFPlots.ipynb. Here, we will compare the new formatting of some examples with their previous formatting. To the best of my knowledge, there is no change in the final PDF and SVG outputs.

1) Basic plot

x = [1,2,3]
y = [2,4,1]
plot(x, y)
print(tikzCode(x, y))

Before:

\begin{axis}\addplot+ coordinates {
(1, 2)
(2, 4)
(3, 1)
};
\end{axis}

After:

\begin{axis}

\addplot+ coordinates {
  (1, 2)
  (2, 4)
  (3, 1)
};

\end{axis}

2) Basic plot with options

a = Axis(Plots.Linear(x, y, legendentry="My Plot"), xlabel="X", ylabel="Y", title="My Title")
a.ylabelStyle = "rotate = -90"
a.legendStyle = "at={(1.05,1.0)}, anchor=north west"
print(tikzCode(a))

Before:

\begin{axis}[legend style = {{at={(1.05,1.0)},anchor=north west}}, ylabel = {Y}, ylabel style = {rotate = -90}, title = {My Title}, xlabel = {X}]\addplot+ coordinates {
(1, 2)
(2, 4)
(3, 1)
};
\addlegendentry{My Plot}
\end{axis}

After:

\begin{axis}[
  legend style = {at={(1.05,1.0)}, anchor=north west},
  ylabel = {Y},
  ylabel style = {rotate = -90},
  title = {My Title},
  xlabel = {X}
]

\addplot+ coordinates {
  (1, 2)
  (2, 4)
  (3, 1)
};
\addlegendentry{My Plot}

\end{axis}

3) Images

f = (x,y)->x*exp(-x^2-y^2)
p = Plots.Image(f, (-2,2), (-2,2))
print(tikzCode(p))

Before:

\begin{axis}[enlargelimits = false, axis on top, colormap={wb}{gray(0cm)=(0); gray(1cm)=(1)}, colorbar]\addplot [point meta min=-0.42870694108441587, point meta max=0.42870694108441587] graphics [xmin=-2, xmax=2, ymin=-2, ymax=2] {tmp_10000000000001.png};
\end{axis}

After:

\begin{axis}[
  enlargelimits = false,
  axis on top,
  colormap={wb}{gray(0cm)=(0); gray(1cm)=(1)},
  colorbar
]

\addplot[
  point meta min = -0.42870694108441587,
  point meta max = 0.42870694108441587
] graphics[
  xmin = -2,
  xmax = 2,
  ymin = -2,
  ymax = 2
] {tmp_10000000000001.png};

\end{axis}

4) Patches

p = Plots.Patch2D([0   1 1 0     1  2 2 1    1   2 2   1;  # x
                   0   0 1 1     0  0 1 1    1   1 2   2;  # y
                   0.2 0 1 1     0 -1 0 1    0.5 1 0.5 0], # color
                  shader = "interp", patch_type="rectangle")
print(tikzCode(p))

Before:

\begin{axis}\addplot[patch type = {rectangle}, shader = {interp}, patch]
table[point meta=\thisrow{c}] {
	x y c
	 0 0 0.2
	 1 0 0
	 1 1 1
	 0 1 1

	 1 0 0
	 2 0 -1
	 2 1 0
	 1 1 1

	 1 1 0.5
	 2 1 1
	 2 2 0.5
	 1 2 0

};
\end{axis}

After:

\begin{axis}

\addplot[
  patch type = {rectangle},
  shader = {interp},
  patch
] table[
  point meta = \thisrow{c}
] {
  x y c
  0 0 0.2
  1 0 0
  1 1 1
  0 1 1

  1 0 0
  2 0 -1
  2 1 0
  1 1 1

  1 1 0.5
  2 1 1
  2 2 0.5
  1 2 0

};

\end{axis}

[mykelk]

Whoa! This is awesome! I'll stress test this over the next couple days on our book and then merge it.

[mykelk]

It works. It's good to go!

[mirkobunse]

Wow, thanks for the quick action!

[MaximeBouton]

This is so cool! many thanks @mirkobunse