title: Plot legend in R using colorRampPalette
body: <p>I have the following code: </p>
  
  <pre><code> values &lt;-as.numeric(logb["apple",])
  </code></pre>
  
  <p>This is a print out of the values (dput(values)) </p>
  
  <pre><code>  c(10.2082514459856, 10.4902973823758, 9.47768668408161, 11.3723768477379, 
  9.77536684750538, -9.96578428466209, 9.84730063667018, -9.96578428466209, 
  -9.96578428466209, 9.67701163699829, 8.89308833957647, -9.96578428466209, 
  -9.96578428466209, -9.96578428466209, 4.88074953878337, 10.8377700714459, 
  9.67240471248415, 11.5511326468668, 12.2959711912287, 11.177615795467, 
  1.27119342003884, 5.89488205689347, 11.0431443899632, 11.5195630239185, 
  8.88611025224185, 0.415935433860163, 10.0909201197081, 1.11935341546107, 
  2.29304065399253, 6.44051757029159, 7.27223875130745, 4.17286046030363, 
  12.2959711912287, 8.93756225545764, -9.96578428466209, 2.82374113821326, 
  -9.96578428466209, -9.96578428466209, 6.7845186590085, 6.75725140640872, 
  3.30799054888394, 1.33285051619047, 11.101382871803, 9.56310340687048, 
  6.05138486988801, 11.1647849791133, 0.641635397441647, 2.25818627743786, 
  6.84610893026537, 0.901701555037384, 5.03961679294633, 8.06503754820301, 
  1.91447713578233, 1.9928923747979, 10.0568354293295, 4.18387614879524, 
  1.44569558279273, 9.44208535287348, 10.7610369594203, 10.072507716131, 
  5.65824078415041, 11.4459048182974, 4.98525549087584, 9.27145968612689, 
  4.62079777510227, -9.96578428466209, -0.158667210269291, 7.84066444448994, 
  10.6469170548272, 8.10132712431389, 10.4213033125177, 7.63017723790216, 
  9.81489035782327, 10.4460595786456, 7.61256542193715, 10.5929209140244, 
  10.6811542795194, 8.63528904198814, 7.08127496996433, 9.37016682222762, 
  9.72611927800663, 8.79221371065147, 11.3773355782529, 10.1340953557389, 
  8.54228484219991, 9.19473410925412, 9.22357213395061, -9.96578428466209, 
  2.06859466822583, 7.85102679919433, 10.2163208336518, 7.32085556502439, 
  7.17868854717394, 7.29012837656103, 9.39064690437556, 11.2182673550456, 
  0.99311790454659, 10.7368071623741, -1.27079596440878, 1.56468983173253, 
  -1.53765829204471, 1.52571260435293, 7.59811777053149, 11.2580431640925, 
  5.76919580165809, 1.46352533364979, 10.6689743752467, -0.193965895767357, 
  -9.96578428466209, -0.109202767044596, 10.2737478964469, 1.86021230860232, 
  0.0522958052916171, 9.1092758724906, 6.75497051676772, -9.96578428466209, 
  7.37624441532334, -1.18384163060835, 10.0953264750968, 10.6621044264772, 
  0.978455308901519, -0.587808292937742, 1.70242105031789, 7.11891286936701, 
  -1.00259671835003, -9.96578428466209, 3.44482984576332, 3.66543195857478, 
  2.30526333330383, 9.25052251950323, 0.476030098407833, 0.677679180622868, 
  0.534955605208228, -9.96578428466209, -0.256817262299128, -0.885928458985493, 
  12.2814393400001, 11.4863572973797, 1.57340309064393, 1.81157359280116, 
  5.2245285179973, 2.82243460348834, 2.63202604954669, 10.9667282364522, 
  11.3976633449755, 6.32855877090442, 3.35147802913235, 1.85503402661645, 
  11.0716881588527, 0.628046239188407, 1.26195497683904, 1.84045926703231, 
  2.36940605873192, 10.7242992203832, 9.033707994836, 0.174047497925867, 
  0.355836934605625, 0.0160116696602818, 8.74355131463472, 10.5306121395554, 
  -1.02983443236526, -9.96578428466209, 11.0009715331005, 2.29188360496881, 
  4.60733173639137, 0.720275634705577, 1.33766127191757, -1.02773392506387
  )
  </code></pre>
  
  <p>I then plot the values, colouring points from smallest to greatest along a colour spectrum:     </p>
  
  <pre><code>    maxColorValue &lt;- 20
      my_palette &lt;- colorRampPalette(c(brewer.pal(11,"Spectral")))(maxColorValue)
      value &lt;- values(dcor, pch=19,col = my_palette[cut(values, maxColorValue),])
  </code></pre>
  
  <p>The resultant plot is correct. I am just not sure how to plot the legend? Presumably this is possible. 
  Thank you </p>