gbrault
/
jupytersketcher
mirror of https://github.com/gbrault/jupytersketcher.git


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772
							

<!doctype html>
<html lang="en" class="no-js">
  <head>
    
      <meta charset="utf-8">
      <meta name="viewport" content="width=device-width,initial-scale=1">
      
      
      <link rel="shortcut icon" href="../assets/images/favicon.png">
      <meta name="generator" content="mkdocs-1.1, mkdocs-material-5.4.0">
    
    
        <title>Learning by Example - Jypyter Sketcher</title>
      
    
      <link rel="stylesheet" href="../assets/stylesheets/main.fe0cca5b.min.css">
      
      
        <link href="https://fonts.gstatic.com" rel="preconnect" crossorigin>
        <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,400i,700%7CRoboto+Mono&display=fallback">
        <style>body,input{font-family:"Roboto",-apple-system,BlinkMacSystemFont,Helvetica,Arial,sans-serif}code,kbd,pre{font-family:"Roboto Mono",SFMono-Regular,Consolas,Menlo,monospace}</style>
      
    
  </head>
  
  
    <body dir="ltr">
  
    
    <input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
    <input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
    <label class="md-overlay" for="__drawer"></label>
    <div data-md-component="skip">
      
        
        <a href="#a-language-to-describe-a-sketch" class="md-skip">
          Skip to content
        </a>
      
    </div>
    <div data-md-component="announce">
      
    </div>
    
      <header class="md-header" data-md-component="header">
  <nav class="md-header-nav md-grid" aria-label="Header">
    <a href=".." title="Jypyter Sketcher" class="md-header-nav__button md-logo" aria-label="Jypyter Sketcher">
      
  
  <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a3 3 0 003-3 3 3 0 00-3-3 3 3 0 00-3 3 3 3 0 003 3m0 3.54C9.64 9.35 6.5 8 3 8v11c3.5 0 6.64 1.35 9 3.54 2.36-2.19 5.5-3.54 9-3.54V8c-3.5 0-6.64 1.35-9 3.54z"/></svg>

    </a>
    <label class="md-header-nav__button md-icon" for="__drawer">
      <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2z"/></svg>
    </label>
    <div class="md-header-nav__title" data-md-component="header-title">
      
        <div class="md-header-nav__ellipsis">
          <span class="md-header-nav__topic md-ellipsis">
            Jypyter Sketcher
          </span>
          <span class="md-header-nav__topic md-ellipsis">
            
              Learning by Example
            
          </span>
        </div>
      
    </div>
    
      <label class="md-header-nav__button md-icon" for="__search">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0116 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 019.5 16 6.5 6.5 0 013 9.5 6.5 6.5 0 019.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5z"/></svg>
      </label>
      
<div class="md-search" data-md-component="search" role="dialog">
  <label class="md-search__overlay" for="__search"></label>
  <div class="md-search__inner" role="search">
    <form class="md-search__form" name="search">
      <input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" data-md-state="active">
      <label class="md-search__icon md-icon" for="__search">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0116 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 019.5 16 6.5 6.5 0 013 9.5 6.5 6.5 0 019.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5z"/></svg>
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12z"/></svg>
      </label>
      <button type="reset" class="md-search__icon md-icon" aria-label="Clear" data-md-component="search-reset" tabindex="-1">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41L17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41z"/></svg>
      </button>
    </form>
    <div class="md-search__output">
      <div class="md-search__scrollwrap" data-md-scrollfix>
        <div class="md-search-result" data-md-component="search-result">
          <div class="md-search-result__meta">
            Initializing search
          </div>
          <ol class="md-search-result__list"></ol>
        </div>
      </div>
    </div>
  </div>
</div>
    
    
  </nav>
</header>
    
    <div class="md-container" data-md-component="container">
      
        
      <main class="md-main" data-md-component="main">
        <div class="md-main__inner md-grid">
          
            
              <div class="md-sidebar md-sidebar--primary" data-md-component="navigation">
                <div class="md-sidebar__scrollwrap">
                  <div class="md-sidebar__inner">
                    <nav class="md-nav md-nav--primary" aria-label="Navigation" data-md-level="0">
  <label class="md-nav__title" for="__drawer">
    <a href=".." title="Jypyter Sketcher" class="md-nav__button md-logo" aria-label="Jypyter Sketcher">
      
  
  <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a3 3 0 003-3 3 3 0 00-3-3 3 3 0 00-3 3 3 3 0 003 3m0 3.54C9.64 9.35 6.5 8 3 8v11c3.5 0 6.64 1.35 9 3.54 2.36-2.19 5.5-3.54 9-3.54V8c-3.5 0-6.64 1.35-9 3.54z"/></svg>

    </a>
    Jypyter Sketcher
  </label>
  
  <ul class="md-nav__list" data-md-scrollfix>
    
      
  <li class="md-nav__item">
    <a href=".." title="Home" class="md-nav__link">
      Home
    </a>
  </li>

    
  <li class="md-nav__item">
    <a href="../about/" title="About" class="md-nav__link">
      About
    </a>
  </li>

    
  <li class="md-nav__item">
    <a href="../presentation/" title="Presentation" class="md-nav__link">
      Presentation
    </a>
  </li>

    
  <li class="md-nav__item md-nav__item--active">
    
    <input class="md-nav__toggle md-toggle" data-md-toggle="toc" type="checkbox" id="__toc">
    
    
      <label class="md-nav__link md-nav__link--active" for="__toc">
        Learning by Example
        <span class="md-nav__icon md-icon">
          <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 9h14V7H3v2m0 4h14v-2H3v2m0 4h14v-2H3v2m16 0h2v-2h-2v2m0-10v2h2V7h-2m0 6h2v-2h-2v2z"/></svg>
        </span>
      </label>
    
    <a href="./" title="Learning by Example" class="md-nav__link md-nav__link--active">
      Learning by Example
    </a>
    
      
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
  
  
    <label class="md-nav__title" for="__toc">
      <span class="md-nav__icon md-icon">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12z"/></svg>
      </span>
      Table of contents
    </label>
    <ul class="md-nav__list" data-md-scrollfix>
      
        <li class="md-nav__item">
  <a href="#a-language-to-describe-a-sketch" class="md-nav__link">
    A language to describe a sketch
  </a>
  
</li>
      
        <li class="md-nav__item">
  <a href="#example" class="md-nav__link">
    Example
  </a>
  
    <nav class="md-nav" aria-label="Example">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#the-final-sketch" class="md-nav__link">
    The final sketch
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#support-files" class="md-nav__link">
    Support files
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-yaml-definition" class="md-nav__link">
    The yaml definition
  </a>
  
    <nav class="md-nav" aria-label="The yaml definition">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#libraries" class="md-nav__link">
    Libraries
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#constants-construction-parameters" class="md-nav__link">
    Constants: Construction parameters
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#frame-core-geometric-parameters" class="md-nav__link">
    Frame: core geometric parameters
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-body-object" class="md-nav__link">
    The body object
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-plan-object" class="md-nav__link">
    The plan object
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-friction-sketch" class="md-nav__link">
    The friction sketch
  </a>
  
</li>
        
      </ul>
    </nav>
  
</li>
        
          <li class="md-nav__item">
  <a href="#using-the-parser" class="md-nav__link">
    Using the parser
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#friction-sketch-hierarchy" class="md-nav__link">
    "friction" sketch hierarchy
  </a>
  
</li>
        
      </ul>
    </nav>
  
</li>
      
    </ul>
  
</nav>
    
  </li>

    
  <li class="md-nav__item">
    <a href="../shapereference/" title="Shapes Reference" class="md-nav__link">
      Shapes Reference
    </a>
  </li>

    
  </ul>
</nav>
                  </div>
                </div>
              </div>
            
            
              <div class="md-sidebar md-sidebar--secondary" data-md-component="toc">
                <div class="md-sidebar__scrollwrap">
                  <div class="md-sidebar__inner">
                    
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
  
  
    <label class="md-nav__title" for="__toc">
      <span class="md-nav__icon md-icon">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12z"/></svg>
      </span>
      Table of contents
    </label>
    <ul class="md-nav__list" data-md-scrollfix>
      
        <li class="md-nav__item">
  <a href="#a-language-to-describe-a-sketch" class="md-nav__link">
    A language to describe a sketch
  </a>
  
</li>
      
        <li class="md-nav__item">
  <a href="#example" class="md-nav__link">
    Example
  </a>
  
    <nav class="md-nav" aria-label="Example">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#the-final-sketch" class="md-nav__link">
    The final sketch
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#support-files" class="md-nav__link">
    Support files
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-yaml-definition" class="md-nav__link">
    The yaml definition
  </a>
  
    <nav class="md-nav" aria-label="The yaml definition">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#libraries" class="md-nav__link">
    Libraries
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#constants-construction-parameters" class="md-nav__link">
    Constants: Construction parameters
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#frame-core-geometric-parameters" class="md-nav__link">
    Frame: core geometric parameters
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-body-object" class="md-nav__link">
    The body object
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-plan-object" class="md-nav__link">
    The plan object
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#the-friction-sketch" class="md-nav__link">
    The friction sketch
  </a>
  
</li>
        
      </ul>
    </nav>
  
</li>
        
          <li class="md-nav__item">
  <a href="#using-the-parser" class="md-nav__link">
    Using the parser
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#friction-sketch-hierarchy" class="md-nav__link">
    "friction" sketch hierarchy
  </a>
  
</li>
        
      </ul>
    </nav>
  
</li>
      
    </ul>
  
</nav>
                  </div>
                </div>
              </div>
            
          
          <div class="md-content">
            <article class="md-content__inner md-typeset">
              
                
                  <h1>Learning by Example</h1>
                
                <h2 id="a-language-to-describe-a-sketch">A language to describe a sketch</h2>
<p>Pysketcher initial version <a href="">HPL Pysketcher</a> enable sketch definition in python. HPL is showing the hierachical nature of sketches. This is implemented via the Composition function. One can further grasp this using the graphviz_dot function applied to discover the composition herarchy implemented as a graphviz image <a href="#friction-sketch-hierarchy">see The hierarchy of the "friction" sketch</a> at the end of this page.</p>
<p>Due to the hierarchical nature of sketches, it is quite straightforward to think about using yaml as the syntax for defining a sketch.</p>
<p>Benefits are the following:</p>
<ul>
<li>Leaner sketch writing as only data relevant to the context needs to be defined</li>
<li>A more straightforward reading for the same reason</li>
<li>A more robust sketch definition <ul>
<li>The same set of rules is applied to generate a sketch</li>
<li>No further python idiom is be intermingled as opposed to the case of python defined sketches</li>
<li>Don't make me wrong! Data defined versus program defined there is no winner, it's just a matter of context</li>
</ul>
</li>
</ul>
<h2 id="example">Example</h2>
<p>This example provides the yaml content to define the Dry Friction case</p>
<h3 id="the-final-sketch">The final sketch</h3>
<p><img alt="dryfriction sketch" src="../images/dryfriction.svg" /></p>
<p>An inclined plan (the A-B edge) supports a blue rectangle which is dragged down by gravity. The plan makes an angle <span><span class="MathJax_Preview">\theta</span><script type="math/tex">\theta</script></span> with the ground level. Sketch implementation notebook includes a controller enabling the <span><span class="MathJax_Preview">\theta</span><script type="math/tex">\theta</script></span> angle to change. The whole plan, including the body, can rotate arround point B.</p>
<h3 id="support-files">Support files</h3>
<p>The example we are developing now is based upon the "Dry Friction mockup" notebook</p>
<ul>
<li>the rendered html version of the notbook can be viewed <a href="../resources/DryFriction.html">here</a></li>
<li>the notebook can be download <a href="../resources/DryFriction.ipynb">here</a></li>
</ul>
<h3 id="the-yaml-definition">The yaml definition</h3>
<p>Sketcher language is defined as a yaml compliant file or string. The yaml file is a dictionnary of "objects". Objects can be regular python objects or sketcher objects.
A skertcher object is composed as follow:</p>
<ul>
<li><strong>a formula</strong>: it's a leaf object, like Rectangle, Circle, Line etc or a composition</li>
<li><strong>a style list</strong>: line or fill colors, line stroke... declared as a yaml hierarchy</li>
<li><strong>a transformation list</strong>: the defined object can be transformed using sketcher transformation: translation, rotation...</li>
</ul>
<p>As a general rule, a new object suppose all parameters to be defined before they are used to construct it.</p>
<p><strong>For example, you can create a circle if the center and the radius have been defined earlier in the file.</strong></p>
<p>The general layout of a sketcher file is as follow:</p>
<ul>
<li><strong>Libraries, Construction Variables, Frame</strong><ul>
<li>declaration of the libraries used by the objects further declared: at least pysketcher is mandatory</li>
<li>various global variable which encompass the "Construction" variables which define the object main physical dimensions, positions...</li>
<li>some "actions" corresponding to executable python sentences<ul>
<li>One mandatory action is the setting of the drawing frame (drawing_tool.set_coordinate_system): it must be declared before any other pysketcher object is used.</li>
<li>Other use case of action is the setting of global parameters like default line color: (drawing_tool.set_linecolor('black')) for example</li>
</ul>
</li>
<li>this is stored in the head string thereafter</li>
<li>The example uses the following objects<ul>
<li>libraries: setting the libraries used for this sketch</li>
<li>constants: all the sketch dimensionning data</li>
<li>frame: all the shapes or geometric objects which will be used by the other shapes</li>
</ul>
</li>
</ul>
</li>
<li><strong>Sketcher Objects</strong><ul>
<li>Usually starting with the declaration of Pysketcher leaf objects (Geometry object like Line, Circle, Rectangle...)</li>
<li>May be aggregated using the composition object</li>
<li>Composition can be made of composition object (recursive behaviour)</li>
<li>Grouping leafs and composition will be further used to apply transformation latter on (based on the "physics")</li>
<li>The example uese three group of shapes<ul>
<li>The body object</li>
<li>The plan object</li>
<li>The friction main object</li>
</ul>
</li>
<li>The plan includes the body</li>
<li>The friction includes the plan (that will be able to rotate as a group) and the ground (will stay fixed)</li>
</ul>
</li>
</ul>
<h4 id="libraries">Libraries</h4>
<pre><code class="python">libraries = {'name': &quot;head&quot;,
'shapes':&quot;&quot;&quot;\
libraries: [&quot;from math import tan, radians, sin, cos&quot;,&quot;from pysketcher import *&quot;]&quot;&quot;&quot;}
</code></pre>

<h4 id="constants-construction-parameters">Constants: Construction parameters</h4>
<pre><code class="python">constants = {'name': &quot;constants&quot;,
'shapes':&quot;&quot;&quot;\
fontsize: 18         # size of the characters
g: 9.81              # constant gravity
theta: 30.0          # inclined plane angle
L: 10.0              # sketch sizing parameter
a: 1.0               #
xmin: 0.0            # sketech min Abscissa
ymin: -3.0           # sketech min Ordinate     
rl: 2.0              # rectangle width
rL: 1.0              # rectangle length
&quot;&quot;&quot;}
</code></pre>

<h4 id="frame-core-geometric-parameters">Frame: core geometric parameters</h4>
<pre><code class="python">frame = {'name': &quot;frame&quot;,
'shapes':&quot;&quot;&quot;\
setframe:            # sketch setup
    action: &quot;drawing_tool.set_coordinate_system(xmin=xmin-L/5, xmax=xmin+1.5*L,ymin=ymin, ymax=ymin+1.5*L,instruction_file='tmp_mpl_friction.py')&quot;
setblackline:        # default frame values and actions
    action: &quot;drawing_tool.set_linecolor('black')&quot;
B: point(a+L,0)                      # wall right end
A: point(a,tan(radians(theta))*L)    # wall left end
normal_vec: point(sin(radians(theta)),cos(radians(theta)))     # Vector normal to wall
tangent_vec: point(cos(radians(theta)),-sin(radians(theta)))   # Vector tangent to wall
help_line: Line(A,B)                 # wall line
x: a + 3*L/10.                       # contact point Abscissa
y: help_line(x=x)                    # contact point Ordinate
contact: point(x, y)                 # contact point: middle of the rectangle bottom edge
c: contact + rL/2*normal_vec
&quot;&quot;&quot;}
</code></pre>

<h4 id="the-body-object">The body object</h4>
<pre><code class="python">body={'name': &quot;body&quot;,
'shapes':&quot;&quot;&quot;\
rectangle: 
    formula: Rectangle(contact, rl, rL)
    style:
        linecolor: blue
        filled_curves: blue
    transform: [&quot;rotate(-theta, contact)&quot;,
                &quot;translate(-rl/2*tangent_vec)&quot;]
N: 
    formula: Force(contact - rl*normal_vec, contact, r'$N$', text_pos='start')
    style:
        linecolor: black
wheel: 
    formula: &quot;Composition({'outer': rectangle})&quot;   
    style:
        shadow: 1
mc:
    formula: Text(r'$c$', c)
body: 
    formula: &quot;Composition({'wheel': wheel, 'N': N, 'mc': mc})&quot;
    style:
        linecolor: black
&quot;&quot;&quot;}
</code></pre>

<h4 id="the-plan-object">The plan object</h4>
<pre><code class="python">plan={'name': &quot;plan&quot;,
'shapes':&quot;&quot;&quot;\
mB:
    formula: Text(r'$B$',B)
mA:
    formula: Text(r'$A$', A)
wall: 
    formula: Wall(x=[A[0], B[0]], y=[A[1], B[1]], thickness=-0.25,transparent=False)
    style:
        linecolor: black    
x_const: 
    formula: Line(contact, contact + point(0,4))
    style:
        linestyle: dotted
    transform: rotate(-theta, contact)
x_axis: 
    formula: &quot;Axis(start=contact+ 2*rl*normal_vec, length=2*rl,label='$x$', rotation_angle=-theta)&quot;
plan: 
    formula: &quot;Composition({'body': body, 'inclined wall': wall, 'x start': x_const, 'x axis': x_axis, 'mA': mA, 'mB': mB})&quot;
&quot;&quot;&quot;}
</code></pre>

<h4 id="the-friction-sketch">The friction sketch</h4>
<pre><code class="python">friction={'name': &quot;friction&quot;,
'shapes':&quot;&quot;&quot;\
mg: 
    formula: Gravity(c, rl, text='$Mg$')
    style:
        linecolor: black
angle: 
    formula: &quot;Arc_wText(r'$&lt;bslash&gt;theta$', center=B, radius=3, start_angle=180-theta, arc_angle=theta, fontsize=fontsize)&quot;
    style:
        linecolor: black
        linewidth: 1
ground: 
     formula: Line((B[0]-L/10., 0), (B[0]-L/2.,0))
     stlye:
         linecolor: black
         linestyle: dashed
         linewidth: 1
friction: 
    formula: &quot;Composition({'plan': plan, 'ground': ground, 'mg': mg, 'angle': angle})&quot;
&quot;&quot;&quot;}
</code></pre>

<h3 id="using-the-parser">Using the parser</h3>
<p>To parse the above example, the following code do the job.</p>
<ol>
<li>libraries, constants and frame must be used first as all the other bits needs one or more variable they defines.</li>
<li>After, any other sketch can be parsed, the order just need to respect precedence (if one object uses another it must be parsed after)</li>
<li>this setting allows naturally a modular definition of sketch objects</li>
</ol>
<p>The parser checks for syntax precedence and warns of any detected error.</p>
<pre><code class="python">myfig = {}
if sketchParse(libraries,myfig):
    if sketchParse(constants,myfig):
        if sketchParse(frame,myfig):
            if sketchParse(body,myfig):
                if sketchParse(plan,myfig):
                    if sketchParse(friction,myfig):
                        print(&quot;success&quot;)
</code></pre>

<h3 id="friction-sketch-hierarchy">"friction" sketch hierarchy</h3>
<p><img alt="" src="../images/dotdryfriction.svg" /></p>
                
              
            </article>
          </div>
        </div>
      </main>
      
        
<footer class="md-footer">
  
    <div class="md-footer-nav">
      <nav class="md-footer-nav__inner md-grid" aria-label="Footer">
        
          <a href="../presentation/" title="Presentation" class="md-footer-nav__link md-footer-nav__link--prev" rel="prev">
            <div class="md-footer-nav__button md-icon">
              <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12z"/></svg>
            </div>
            <div class="md-footer-nav__title">
              <div class="md-ellipsis">
                <span class="md-footer-nav__direction">
                  Previous
                </span>
                Presentation
              </div>
            </div>
          </a>
        
        
          <a href="../shapereference/" title="Shapes Reference" class="md-footer-nav__link md-footer-nav__link--next" rel="next">
            <div class="md-footer-nav__title">
              <div class="md-ellipsis">
                <span class="md-footer-nav__direction">
                  Next
                </span>
                Shapes Reference
              </div>
            </div>
            <div class="md-footer-nav__button md-icon">
              <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4z"/></svg>
            </div>
          </a>
        
      </nav>
    </div>
  
  <div class="md-footer-meta md-typeset">
    <div class="md-footer-meta__inner md-grid">
      <div class="md-footer-copyright">
        
        Made with
        <a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
          Material for MkDocs
        </a>
      </div>
      
    </div>
  </div>
</footer>
      
    </div>
    
      <script src="../assets/javascripts/vendor.d710d30a.min.js"></script>
      <script src="../assets/javascripts/bundle.b39636ac.min.js"></script><script id="__lang" type="application/json">{"clipboard.copy": "Copy to clipboard", "clipboard.copied": "Copied to clipboard", "search.config.lang": "en", "search.config.pipeline": "trimmer, stopWordFilter", "search.config.separator": "[\\s\\-]+", "search.result.placeholder": "Type to start searching", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents"}</script>
      
      <script>
        app = initialize({
          base: "..",
          features: [],
          search: Object.assign({
            worker: "../assets/javascripts/worker/search.a68abb33.min.js"
          }, typeof search !== "undefined" && search)
        })
      </script>
      
        <script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/MathJax.js?config=TeX-MML-AM_CHTML"></script>
      
    
  </body>
</html>