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HTML

<div class="prewrap">
<div class="pretitle">
    Vector field describing ($dr/d\theta$, r) for the parabola $y = x^2$ (matlab code)
    <div class="codeclick">Click to show code</div>
</div>
<pre>
x = -2:.01:2
y = x.^2
plot(x, y)
hold on
xvec = -1.8:0.2:1.8
yvec = xvec.^2
scatter(xvec, yvec)
vvec = sqrt(xvec.^2 + yvec.^2)
uvec = vvec ./ xvec
quiver(xvec, yvec, uvec, vvec)
</pre>
</div>

JavaScript

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