title: R: weird y-axis in frequency/density plot (ggplot2)
body: <p>I have data from two samples and I want to plot a frequency distribution plot in R. I have the reference done in Excel:</p>
  
  <p><img src="https://i.stack.imgur.com/QW4i2.jpg" alt="what in want to get in R (obtained with excel)"></p>
  
  <p>I uploaded in R the data (HistSerp). It's <code>136 obs. of 2 variables</code>. </p>
  
  <pre><code>summary(HistSerp)
  V1              V2       
   Min.   :0.000   Min.   :0.0000  
  1st Qu.:0.000   1st Qu.:0.3752  
  Median :0.000   Median :1.2845  
  Mean   :0.055   Mean   :1.2144  
  3rd Qu.:0.082   3rd Qu.:1.9952  
  Max.   :1.082   Max.   :2.9800 
  
  class(HistSerp$V1)
  "numeric"
  class(HistSerp$V2)
  "numeric"
  </code></pre>
  
  <p>If I <code>HistSerp.m &lt;- melt(HistSerp)</code> and <code>ggplot(HistSerp.m) + geom_freqpoly(aes(x = value,
                                   y = ..density.., colour = variable))</code>
  the plot looks:<img src="https://i.stack.imgur.com/Wz5PI.png" alt="enter image description here"></p>
  
  <p>I don't know why the y-axis span that values, and I'm not sure if it's only a y-axis labeling problem, the plot itself seems different.
  I've also tried <code>geom_density()</code> , <code>hist(HistSerp$V1, freq=FALSE)</code>, etc. but I can't get it as I expect, I got the same as before. I guess there's something wrong with my data but I can't figure out what is it. Any help will be appreciated.</p>
  
  <p>Thanks</p>
  
  <p>Ps. should I copy the data (136x2)?</p>
  
  <p>Update: The data. Sorry if there's a better way to copy it...</p>
  
  <pre><code>0.144   2.024
  0.082   2.548
  0.082   1.943
  0.000   2.599
  0.000   2.233
  0.000   2.342
  0.082   1.655
  0.082   2.200
  0.000   2.261
  0.000   2.408
  0.000   2.127
  0.000   2.053
  0.000   1.929
  0.000   1.413
  0.000   2.400
  0.000   2.777
  0.000   2.685
  0.000   1.436
  0.000   1.573
  0.000   2.504
  0.000   1.533
  0.000   1.434
  0.000   1.421
  0.000   2.534
  0.082   1.728
  0.000   1.984
  0.082   1.287
  0.000   2.324
  0.164   2.405
  0.279   1.989
  0.082   2.729
  0.144   2.046
  0.226   2.496
  0.000   2.980
  0.000   2.634
  0.000   1.792
  0.000   1.571
  0.000   0.612
  0.000   0.884
  0.000   0.449
  0.000   2.318
  0.082   0.449
  0.000   0.449
  0.000   0.563
  0.082   0.919
  0.000   0.617
  0.082   1.297
  0.144   0.719
  0.000   1.897
  0.000   1.338
  0.000   0.337
  0.000   1.555
  0.000   0.273
  0.291   0.656
  0.000   0.273
  0.082   0.388
  0.082   1.911
  0.082   0.852
  0.000   1.580
  0.000   1.450
  0.000   1.209
  0.000   2.049
  0.082   2.694
  0.082   1.089
  0.246   2.643
  0.000   2.393
  0.000   1.702
  0.000   2.595
  0.000   1.432
  0.000   2.094
  0.000   1.526
  0.082   1.775
  0.000   0.273
  0.000   1.405
  0.000   2.014
  0.000   0.543
  0.000   0.586
  0.000   1.224
  0.000   0.719
  0.164   0.201
  0.000   0.388
  0.082   0.232
  0.000   0.116
  0.000   0.116
  0.082   1.395
  0.000   0.116
  0.000   0.232
  0.082   0.844
  0.000   1.153
  0.082   0.000
  0.667   0.000
  0.000   1.535
  0.000   2.687
  0.000   0.922
  0.226   0.337
  0.197   0.999
  1.082   1.373
  0.082   0.396
  0.082   0.116
  0.000   1.667
  0.000   0.731
  0.000   0.544
  0.082   2.072
  0.000   2.262
  0.164   2.111
  0.082   1.675
  0.000   0.116
  0.000   0.232
  0.082   0.116
  0.000   1.004
  0.000   0.116
  0.164   0.116
  0.082   0.699
  0.000   0.000
  0.000   0.273
  0.082   0.000
  0.000   0.388
  0.082   0.000
  0.000   0.116
  0.000   0.273
  0.000   0.000
  0.000   0.649
  0.164   0.000
  0.082   0.000
  0.082   0.000
  0.000   0.000
  0.082   0.000
  0.144   1.282
  0.000   1.772
  0.000   0.116
  0.082   0.000
  0.000   1.416
  0.000   0.563
  0.082   0.510
  0.000   0.316
  0.164   1.124
  </code></pre>