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Graphic Images, TikZImages

This example shows how to create an image/plot using Tikz.

Problem Techniques Index

PG problem file Explanation

Initialization: It is important to include the PGtikz.pl macro.

$graph_image = createTikZImage();
# Only change the extenstion if the display mode is not TeX.  The extension is automatically set
# to 'pdf' by the macro if the display mode is TeX, and this overrides that which breaks
# hardcopy generation.
$graph_image->ext('svg') if $displayMode ne 'TeX';

# Randomization
$a = non_zero_random(-6,6);  # horizonatal translation
$b = random(-4,4);           # vertical translation

\draw[<->,thick] (-11,0) -- (11,0) node[above left,outer sep=2pt]{\(x\)};
\draw[<->,thick] (0,-11) -- (0,11) node[below right,outer sep=2pt]{\(y\)};
\foreach \x in {-10,-8,...,-2,2,4,...,10} \draw[thin] (\x,5pt) -- (\x,-5pt) node[below]{\(\x\)};
\foreach \y in {-10,-8,...,-2,2,4,...,10} \draw[thin] (5pt,\y) -- (-5pt,\y) node[left]{\(\y\)};
\draw[<->,red] plot[domain={-3.2+$a}:{3.2+$a}] (\x,{pow(\x-$a,2)+$b});


  • The createTikZImage() function creates an image to be built using tikz.
  • The $graph_image->ext('svg') if $displayMode ne 'TeX'; will generate a SVG image, which will generally look better than PNG.
  • The $graph_image->tikzLibraries("arrows.meta"); will load the arrows.meta Tikz library.
  • pg variables $a and $b are defined for use in the TikZ code that follows. If the TikZ code references non-existent pg variables the image creation fails silently.
  • The actual tikz image is built between $graph_image->BEGIN_TIKZ and END_TIKZ
  • Notes: on using this and related Contexts.


[@ image(insertGraph($graph_image), width => 300, tex_size => 1000) @]*


Main Text: This is how to insert the tikz image. Note the width and tex_size parameters can change the size of the image on the web and as hardcopy.


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Problem Techniques Index