MathML-in-SVG

library(minisvg)

Introduction

Literal SVG and HTML strings can be included using the SVGLiteral R6 class.

This may be useful when:

• You have a character string containing SVG text from an external source to include directly into your document.
• You have literal HTML that you’d like to include as a <foreignObject> within the SVG
• You have an object which can be coerced to a character string e.g. a minihtml document

MathML

MathML is an markup language for describing mathematical notation.

mathml <- '
<math xmlns = "http://www.w3.org/1998/Math/MathML">
   <mrow>
      <mi>A</mi>
      <mo>=</mo>

      <mfenced open = "[" close="]">

         <mtable>
            <mtr>
               <mtd><mi>x</mi></mtd>
               <mtd><mi>y</mi></mtd>
            </mtr>

            <mtr>
               <mtd><mi>z</mi></mtd>
               <mtd><mi>w</mi></mtd>
            </mtr>
         </mtable>

      </mfenced>
   </mrow>
</math>'

Inserting literal HTML into an SVG

• Create a <foreignObject>
• Add an SVGLiteral node to the <foreignObject>

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create an SVG document with a grey rectangle
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doc <- svg_doc()
doc$rect(x = "10%", y = "10%", width = "80%", height = "80%", fill = "silver")

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a literal node with the mathml
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lit <- SVGLiteral$new(mathml)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a foreign object and add the literal object to it.
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fo <- stag$foreignObject(x = 50, y = 50, width = 100, height = 100)
fo$append(lit)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# append the foreign object to the document
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doc$append(fo)

doc