title: using R to plot interaction plot
body: <p>I have created a model using following</p>
  
  <pre><code>      age    hrs  charges
   530.6071 792.10  3474.60
   408.6071 489.70  1247.06
   108.0357 463.00  1697.07
   106.6071 404.15  1676.33
   669.4643 384.65  1701.13
   556.4643 358.15  1630.30
   665.4643 343.85  2468.83
   508.4643 342.35  3366.44
   106.0357 335.25  2876.82
  
  interaction_model &lt;- rlm( charges~age+hrs+age*hrs, age_vs_hrs_charges_cleaned);
  </code></pre>
  
  <p>Any idea how i can plot this in 3D?</p>
  
  <p>I already plotted using </p>
  
  <pre><code>library(effects);
  plot(effect(term="age:hrs", mod=interaction_model,default.levels=20),multiline=TRUE);
  </code></pre>
  
  <p>but this is not very clear visualization.</p>
  
  <p>Any help?</p>