Table-aligned, randomized, repeatingly smaller icons for eyesight-chart

Question

My daughter needs to train her eyesight in accordance to the LEA eyesight chart tests.

I have manually created a new chart for her, but it really takes a long time randomzing the four icons and manually aligning them:

I was thinking about automating the process using LaTeX. I have all four icons as separate PDFs (also any other vector format can be derived from that, of course). Would anyone care to help me with this, as I assume it is rather more a "programming LaTeX" then "writing in LaTeX" task ;) I'd be very happy to share the result with a good friend of mine who is a pediatrician as I assume it might help others, too (they give out copies of an old copy of a fax someone received back in the 80's... - not very clean and not much help, either).

If someone could help me I'd be extremely grateful. The distance between each line and the decrease in size can be guessed but should be alterable.

Answer 1

One way to accomplish this is to use pgfmathdeclarerandomlist{<list name>}{{order 1}{order 2}...{order 24}} to specify all the possible combinations of the pictures, and then use \pgfmathrandomitem to randomly pick one of these and use that as the order of the pictures.

The images are placed in a table with \TableRow{<scale>}, where the <scale> specifies the scale to be applied to the images in that row.

Notes:

• To increase the spacing between the rows you can include a size at the end of each row. For example: \\[0.3cm].

Further Enhancements:

• The array of possible combinations should be auto generated.

Code:

For this to work I saved the images as 1.png, 2.png, 3.png, 4.png in the directory where I had this .tex file.

\documentclass{article}
\usepackage{graphicx}
\usepackage{xstring}
\usepackage{pgf}
% All possible combination of pictures
% Listed here in increasing numerical order for convenience
\pgfmathdeclarerandomlist{MyRandomList}{%
    {1234} {2134} {3124} {4123}
    {1243} {2143} {3142} {4132}
    {1324} {2314} {3214} {4213}
    {1342} {2341} {3241} {4232}
    {1423} {2413} {3412} {4312}
    {1432} {2431} {3421} {4321}
}
\newcommand{\MaxWidth}{2.0}%  width in cm
\newcommand{\MaxHeight}{2.0}% height in cm
\newcommand{\MyIncludeGraphics}[3]{% #1= scale
    \pgfmathsetmacro{\Width}{#1\MaxWidth}%
    \pgfmathsetmacro{\Height}{#1*\MaxHeight}%
    \StrChar{#2}{#3}[\FigureToInclude]% Extract digit from the 4 digit random number
    \includegraphics[width=\Width cm, height=\Height cm]{\FigureToInclude}%
}%
\newcommand*{\TableRow}[1]{%
    \pgfmathrandomitem{\RamdomMemberOfList}{MyRandomList}
    \xdef\OrderOfPictures{\RamdomMemberOfList}
    \MyIncludeGraphics{#1}{\OrderOfPictures}{1} &
    \MyIncludeGraphics{#1}{\OrderOfPictures}{2} &
    \MyIncludeGraphics{#1}{\OrderOfPictures}{3} &
    \MyIncludeGraphics{#1}{\OrderOfPictures}{4}
}%
\begin{document}
\begin{tabular}{c c c c}
    \TableRow{1.0}\
    \TableRow{0.8}\
    \TableRow{0.6}\
    \TableRow{0.4}\
    \TableRow{0.3}\
    \TableRow{0.2}\
    \TableRow{0.1}\
\end{tabular}
\end{document}