title: ggplot plots error bars but not actual data points in R
body: <p>I have a dataframe read in from a .csv which looks like this:</p>
  
  <p>valley_cw_summary:</p>
  
  <pre><code>"","times","means","sd"
  "1",1,23.7326530612245,0.822951942679513
  "2",10,NA,NA
  "3",11,27.9811602527283,2.18451736644603
  "4",12,NA,NA
  "5",13,28.8594485927628,2.47839597165728
  "6",14,NA,NA
  "7",15,28.5562894887995,2.4613545973872
  "8",16,NA,NA
  "9",17,26.9750287026406,1.87035639782657
  "10",18,NA,NA
  "11",19,25.2288340034463,1.0835585618286
  "12",2,NA,NA
  "13",20,NA,NA
  "14",21,24.5269385410684,0.804365453635496
  "15",22,NA,NA
  "16",23,24.1512923607122,0.806920352501217
  "17",24,NA,NA
  "18",25,24.0809803921569,0.826911680243558
  "19",3,23.5923254472014,0.889646609799541
  "20",4,NA,NA
  "21",5,23.3741488747836,0.932515616519176
  "22",6,NA,NA
  "23",7,23.2863296955773,0.982225553711973
  "24",8,NA,NA
  "25",9,25.4694252873563,1.33025859840695
  </code></pre>
  
  <p>I attempt to plot this with the following script:</p>
  
  <pre><code>ggplot(data=valley_c_w_summary,aes(x = times,y=means))+
    theme_classic()+
    geom_line(data = valley_c_w_summary,aes(x=times,y=means))+
    geom_errorbar(data=valley_c_w_summary,aes(ymin=means-sd,ymax=means+sd))+
    labs(x="Time",y="Temperature in canopy May to December")
  </code></pre>
  
  <p>This plots only error bars (centered around the appropriate points as far as I can tell). I am plotting it with other such dataframes on the same plot, and they work fine, but they don't have any "NA"s, which leads me to believe they are the culprit. The full script of which looks like:</p>
  
  <pre><code>ggplot(data=ridge_cw_summary,aes(x = times,y=means))+
    geom_errorbar(data=ridge_c_w_summary,aes(ymin=means-sd,ymax=means+sd),colour="red")+
    geom_line(aes(y=means),colour="red")+
    theme_classic()+
    geom_line(data = valley_c_w_summary,aes(x=times,y=means))+
    geom_errorbar(data=valley_c_w_summary,aes(ymin=means-sd,ymax=means+sd))+
    geom_line(data = edge_c_w_summary,aes(x=times,y=means),colour="blue")+
    geom_errorbar(data=edge_c_w_summary,aes(ymin=means-sd,ymax=means+sd),colour="blue")+
    labs(x="Time",y="Temperature in canopy May to December")
  </code></pre>
  
  <p>How can I get ggplot to display the proper points?</p>