Files

<pl-question-panel>
  <p>
    The examples below illustrate some concrete, more advanced use cases for 
    <a href="https://prairielearn.readthedocs.io/en/latest/elements/pl-sketch"><code>pl-sketch</code></a> 
    and how they can be implemented. For convenience, all examples allow blank submissions.
  </p>
</pl-question-panel>

<pl-card>
  <pl-question-panel>
    <p>To grade curves drawn with <code>pl-sketch</code> tools like <code>free-draw</code>, 
      <code>spline</code> or <code>polyline</code>, it is often easiest to compare them to a 
      reference function via the <code>match-function</code> grading criterion. This criterion
      can also be used for partial or piecewise functions when the comparison is delimited by an
      <code>x-range</code> parameter.
    </p>
    <p>For full marks, draw the function 
    
    $$
      f(x) = 
      \begin{cases} 
        x &amp; \text{if } x &lt; 0 \\
        x^2   &amp; \text{if } x \geq 0 
      \end{cases}.
    $$</p>
  </pl-question-panel>
  <pl-sketch answers-name="sketch-segments" x-range="-3,3" y-range="-5,5" allow-blank="true">
    <pl-sketch-tool id="fd" type="free-draw"></pl-sketch-tool>
    <pl-sketch-grade type="match-function" tool-id="fd" function="x" x-range=",0"></pl-sketch-grade> 
    <pl-sketch-grade type="match-function" tool-id="fd" function="x**2" x-range="0,"></pl-sketch-grade> 
    <pl-sketch-solution tool-id="fd" function="x" x-range=",0"></pl-sketch-solution>
    <pl-sketch-solution tool-id="fd" function="x**2" x-range="0,"></pl-sketch-solution>
  </pl-sketch>
</pl-card>

<pl-card>
  <pl-question-panel>
    <p>When splitting up grading criteria as in the example above, giving partial points per criterion 
      is often desirable. To prevent giving any partial marks unless the full function is correct, it 
      is possible to use <code>stage</code> parameters and a dummy criterion that assigns points when all
      other grading criteria are satisfied.
    </p>
    <p>For full marks, draw the function 
    
    $$
      f(x) = 
      \begin{cases} 
        x &amp; \text{if } x &lt; 0 \\
        x^2   &amp; \text{if } x \geq 0 
      \end{cases}.
    $$</p>
  </pl-question-panel>
  <pl-sketch answers-name="sketch-stage" x-range="-3,3" y-range="-5,5" allow-blank="true">
    <pl-sketch-tool id="fd" type="free-draw"></pl-sketch-tool>
    <pl-sketch-grade type="match-function" tool-id="fd" function="x" x-range=",0" stage="1" weight="0" feedback="Your sketch is incorrect in the interval $[-\infty, 0]$."></pl-sketch-grade> 
    <pl-sketch-grade type="match-function" tool-id="fd" function="x**2" x-range="0," stage="1" weight="0" feedback="Your sketch is incorrect in the interval $[0, \infty]$."></pl-sketch-grade>
    <pl-sketch-grade type="less-than" tool-id="fd" y="5" weight="1" stage="2" feedback="Your sketch needs to match the entire function to earn any points!"></pl-sketch-grade> 
    <pl-sketch-solution tool-id="fd" function="x" x-range=",0"></pl-sketch-solution>
    <pl-sketch-solution tool-id="fd" function="x**2" x-range="0,"></pl-sketch-solution>
  </pl-sketch>
</pl-card>

<pl-card>
  <pl-question-panel>
    <p>The <code>xy-flip</code> parameter allows the grading of curves that represent functions of $y$.
      Because this parameter also changes the interpretation of some grading criteria, we recommend
      testing question with this parameter carefully to make sure they match the expected grading logic.
    </p>
    <p>For full marks, draw the curve $x = y^2$.</p>
  </pl-question-panel>
  <pl-sketch answers-name="sketch-xyflip" x-range="-5,5" y-range="-3,3" allow-blank="true">
    <pl-sketch-tool id="fd" type="free-draw"></pl-sketch-tool>
    <pl-sketch-grade type="match-function" tool-id="fd" function="y**2" xy-flip="true"></pl-sketch-grade> 
  </pl-sketch>
</pl-card>