JuliaPlots/Plots.jl

aspect_ratio not working expectedly with PGFPlotsX

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#4,766 opened on Jun 8, 2023

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PGFPlotsXbuggood first issue

Description

Details

When plotting heatmap with PGFPlotsX backend, I want to have aspect_ratio = 1. The following script

using Plots
pgfplotsx()

heatmap([1, 2, 3, 4], [1, 2, 3, 4], [1 2 1 0 ; 1  3 4 5; 1 0 0 1; 1 9 0 8], aspect_ratio = :equal)

gives the following figure: The x axis of this plot is of course too wide; but then, the following script aimed to solve the problem by fixing the x range eliminates the effect of aspect_ratio = :equal:

using Plots
pgfplotsx()

heatmap([1, 2, 3, 4], [1, 2, 3, 4], [1 2 1 0 ; 1  3 4 5; 1 0 0 1; 1 9 0 8], 
aspect_ratio = :equal, xlim=(0.5, 4.5))

By inspecting the LaTeX code generated, the problem seems to be that heatmap, when asked to generate a figure with aspect_ratio = :equal, simply adjusts the scale of the x axis so that the main body of the heatmap becomes a square; but this is not what is intuitively expected: there is an axis equal image option for the axis environment in tikz, and, IMHO, this is what should be invoked when the aspect_ratio = :equal option is used.

Backends

This bug occurs on ( insert x below )

Backend yes no untested
gr (default)
pythonplot
plotlyjs
pgfplotsx x
unicodeplots
inspectdr
gaston

Versions

Plots.jl version: [91a5bcdd] Plots v1.36.1 Backend version (]st -m <backend(s)>): [8314cec4] PGFPlotsX v1.5.1 Output of versioninfo():

Julia Version 1.7.3
Commit 742b9abb4d (2022-05-06 12:58 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, tigerlake)

Contributor guide

Tech stack
None
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Familiarity with Plots.jlUnderstanding of PGFPlotsX backendBasic knowledge of LaTeX/tikz
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35
Research direction
Investigate the PGFPlotsX backend's handling of aspect ratio attribute. Look at the source files (likely in src/backends/pgfplotsx.jl) to see how aspect ratio is currently implemented. The issue suggests that the backend adjusts axis scale instead of using the 'axis equal image' LaTeX option. Consider modifying the LaTeX generation to use 'axis equal image' when aspect ratio is set to :equal. Test with the provided heatmap script to ensure the plot renders correctly.
aspect_ratio not working expectedly with PGFPlotsX · JuliaPlots/Plots.jl#4766 | Good First Issue