3. Backtracking 1 step diagram - automated

The LaTeX in this section is for one 1-step backtracking diagram.

The values in the diagram can be randomly generated by python.

The required LaTeX and python files are:

backtrack_1step_template.tex

backtrack_1step_diagram_template.tex

backtracking_1step_diagram_maker.py

The 2 custom python modules required are:

backtracking_functions.py

magick_pdf_to_png.py

The python file, backtracking_1step_diagram_maker, when run, will ask for 2 inputs:

Choose the arithmetic process: "Enter 1, 2, 3, 4 or 5 for +, -, X, /, random"

Choose the file name base: "Enter the base filename to be added to the prefix bt1_:".

The filename will have “_q” added for the question diagram and “_ans” for the answer diagram.

e.g. If the user inputs “add1a” the file name will be “bt1_add1a_q”.

---

3.1. A 1-step backtracking diagram with answers

addition_q

png pdf tex

addition_ans

png pdf tex

subtraction_q

png pdf tex

subtraction_ans

png pdf tex

multiplication_q

png pdf tex

multiplication_ans

png pdf tex

division_q

png pdf tex

division_ans

png pdf tex

---

3.2. Splitting the LaTeX and modifying it for python

The LaTeX from a single 1-step equation is used as a starting point, split into two parts and modified to form 2 templates.

The Document template contains the preamble and the scaffold for the document.

The Diagram template contains the backtacking diagram LaTeX.

3.2.1. Document template

The LaTeX 1-step worksheet template is below.

document_template.tex

% backtracking worksheet template
\documentclass[border = 1mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary {arrows.meta}

\tikzset{backtrack/.style={rectangle,draw=black,fill=white,
inner sep=2pt,minimum height=32pt, minimum width=20mm}}
\tikzset{backtrackeq/.style={rectangle,draw=black,fill=white,
inner sep=2pt,minimum height=12pt, minimum width=20mm}}
\tikzset{backtrackstep/.style={rectangle,draw=none,fill=white,
inner sep=2pt,minimum height=12pt, minimum width=20mm}}

\begin{document}
    <<diagram>>
\end{document}

<<diagram>> is placeholder text for the text that python will use to add the LaTeX for the backtracking diagram.

3.2.2. Diagram template

The LaTeX 1-step diagram template is below.

diagram_template.tex

\begin{tikzpicture}

    \node[backtrack] (boxA) at (0, 0) {$<<boxA>>$};
    \node[backtrack] (boxB) [right=1cm of boxA] {$<<boxB>>$};
 
    \node[backtrackeq] (boxAeq) [below=-1pt of boxA] {$=$};
    \node[backtrackeq] (boxBeq) [below=-1pt of boxB] {$=$};

    \node[backtrack] (boxArev) [below=-1pt of boxAeq] {$<<boxArev>>$};
    \node[backtrack] (boxBrev) [below=-1pt of boxBeq] {$<<boxBrev>>$};

    \node(boxAr) at ([yshift=24pt,xshift=5mm]boxA) { };
    \node(boxBl) at ([yshift=24pt,xshift=-5mm]boxB) { };
    \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxAr)  --node[backtrackstep, above=3.0pt] {$<<stepAB>>$} (boxBl);
    
    \node(boxBrevl) at ([yshift=-24pt,xshift=-5mm]boxBrev) { };
    \node(boxArevr) at ([yshift=-24pt,xshift=5mm]boxArev) { };
    \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxBrevl)  --node[backtrackstep, below=3.0pt] {$<<stepABrev>>$} (boxArevr);

\end{tikzpicture}

3.2.3. Example of a placeholder

The line \node[backtrack] (boxB) [right=1cm of boxA] {$<<boxB>>$} has a placeholder <<boxB>> which is replaced by python.

Other placeholders are marked by << >>.

3.2.4. Python to create a 1 step diagram

The Python to create a 1 step diagram is below.

This script creates a LaTeX file with a diagram and converts it to PDF and PNG formats. It does the following steps:

• This Python code requires two user inputs: a1 to 4 to choose the arithmetic operation, and the filename to be used.

• The code reads in three template files: tex_template_path, texans_template_path, and tex_diagram_template_path. The contents of these files are stored in the variables tex_template_txt, tex_template_txt_ans, and tex_diagram_template_txt, respectively.

• The code then calls the make1_diagram function, passing in tex_diagram_template_txt as an argument. kv = btf.get_1step_process_dict() gets the dictionary containing the values to be placed in the diagram template. The make1_diagram function generates a diagram and returns two values: diagram_text and diagram_text_ans. These values are then used to replace the <<diagram>> placeholder in the tex_template_txt and tex_template_txt_ans variables.

• The resulting text is then written to two output files: tex_output_path and tex_output_path_ans.

• The code then waits for 1 second to ensure that the files have been created before calling the convert_to_pdf function to convert these TeX files to PDFs. The PDFs are saved to the paths specified by the pdf_path and pdf_path_ans variables.

• After waiting for another second, the code calls the magick_pdf_to_png.convert_pdf_to_png function to convert the PDFs to PNGs. The PNGs are saved to the paths specified by the png_path and png_path_ans variables.

• The script prints “starting” and “finished” messages to indicate when it begins and ends its execution.

python 1step diagram maker.py

from pathlib import Path
import subprocess
import os
import time
import random
import magick_pdf_to_png
import backtracking_functions as btf

currfile_dir = Path(__file__).parent
tex_template_path = currfile_dir / "backtrack_1step_template.tex"
texans_template_path = currfile_dir / "backtrack_1step_template.tex"
tex_diagram_template_path = currfile_dir / "backtrack_1step_diagram_template.tex"


def convert_to_pdf(tex_path, outputdir):
    tex_path = Path(tex_path).resolve()
    outputdir = Path(outputdir).resolve()
    # for testing
    # print(f"tex_path: {tex_path}")
    # print(f"outputdir: {outputdir}")
    try:
        # Generate the PDF
        subprocess.run(["latexmk", "-pdf", "-outdir=" + str(outputdir), str(tex_path)], check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        # # Clean auxiliary files after successful PDF generation
        subprocess.run(["latexmk", "-c", "-outdir=" + str(outputdir), str(tex_path)], check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        # for hosted remove stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL for debugging any errors
        # Remove the .tex file manually
        if tex_path.exists():
            os.remove(tex_path)
    except subprocess.CalledProcessError as e:
        print(f"Error: {e}")


# tex_keys = ['stepAB','stepABrev','boxA','boxB','boxBrev', 'boxArev' ]
tex_keys_q = ["stepAB", "boxA", "boxBrev"]


def make1_diagram(tex_diagram_template_txt, num):
    tex_diagram_template_txt_ans = tex_diagram_template_txt
    kv = btf.get_1step_process_dict(num)
    for key, value in kv.items():
        tex_diagram_template_txt_ans = tex_diagram_template_txt_ans.replace(
            "<<" + key + ">>", value
        )
    for key, value in kv.items():
        if key in tex_keys_q:
            tex_diagram_template_txt = tex_diagram_template_txt.replace(
                "<<" + key + ">>", value
            )
        else:
            tex_diagram_template_txt = tex_diagram_template_txt.replace(
                "<<" + key + ">>", ""
            )
    return tex_diagram_template_txt, tex_diagram_template_txt_ans


def main():
    num = input("Enter 1, 2, 3, 4 or 5 for +, -, X, /, random \n")
    if num.strip().isdigit():
        num = int(num)
        if not num in [1, 2, 3, 4, 5]:
            num = 5  # random by default
    else:
        num = 5  # random by default
    filename = input("Enter the base filename to be added to the prefix bt1_: \n")
    if not filename:
        filename = "1"  # "bt1_1st_q and bt1_1st_ans as default file"
    # set names of files that are made
    # questions
    tex_output_path = currfile_dir / f"bt1_{filename}_q.tex"
    pdf_path = currfile_dir / f"bt1_{filename}_q.pdf"
    png_path = currfile_dir / f"bt1_{filename}_q.png"

    # answers
    tex_output_path_ans = currfile_dir / f"bt1_{filename}_ans.tex"
    pdf_path_ans = currfile_dir / f"bt1_{filename}_ans.pdf"
    png_path_ans = currfile_dir / f"bt1_{filename}_ans.png"

    # Read in the LaTeX template file
    with open(tex_template_path, "r") as infile:
        tex_template_txt = infile.read()
    # Read in the LaTeX template file for answers
    with open(texans_template_path, "r") as infile:
        tex_template_txt_ans = infile.read()
    # Read in the LaTeX diagram template file
    with open(tex_diagram_template_path, "r") as infile:
        tex_diagram_template_txt = infile.read()

    # Generate the <<diagram>> replacement tex
    diagram_text, diagram_text_ans = make1_diagram(tex_diagram_template_txt, num)
    # Replace the <<diagram>> placeholder in the LaTeX template
    tex_template_txt = tex_template_txt.replace("<<diagram>>", diagram_text)
    tex_template_txt_ans = tex_template_txt_ans.replace("<<diagram>>", diagram_text_ans)
    # Write the question diagram tex to an output file
    with open(tex_output_path, "w") as outfile:
        outfile.write(tex_template_txt)
    # Write the answer diagram tex to an output file
    with open(tex_output_path_ans, "w") as outfile:
        outfile.write(tex_template_txt_ans)

    # Wait for the files to be created
    time.sleep(1)
    # convert to pdf
    convert_to_pdf(tex_output_path, currfile_dir)
    convert_to_pdf(tex_output_path_ans, currfile_dir)

    # Wait for the files to be created
    time.sleep(1)
    # convert to png
    magick_pdf_to_png.convert_pdf_to_png(pdf_path, png_path)
    magick_pdf_to_png.convert_pdf_to_png(pdf_path_ans, png_path_ans)


if __name__ == "__main__":
    print("starting")
    main()
    print("finished")