title: Specify colours in geompoint for variable - ggplot R
body: <p>I am using ggplot with ggmap and following is the command I am using,</p>
  
  <pre><code>print(ggmap(m) + 
          geom_point(aes(x=ga_long, y=ga_lat, color = variable1, size = size) , data=il) + 
          scale_size_continuous(range = c(1,5)) + 
          xlab("Latitude") + ylab("Longitude") 
        # + scale_colour_continuous( c("green", "black", "red"))
  )
  </code></pre>
  
  <p>Here for the color, I have given variable1. It seems to work fine, but I want to specify the colours as I am not comfortable with the already present colours. If there are three factors in the variable1, I would like to give green, black, red as combinations for specific factors. I've tried the following,</p>
  
  <pre><code>   print(ggmap(m) + 
              geom_point(aes(x=ga_long, y=ga_lat, color = 
                               ifelse(variable1 == 0, 'green', 
                                      ifelse(variable1 == 1, 'black', 'red')), size = size),  data=il) + 
              scale_size_continuous(range = c(1,5)) + 
              xlab("Latitude") + ylab("Longitude") 
            # + scale_colour_continuous( c("green", "black", "red"))
      )
  </code></pre>
  
  <p>But this one didn't help. </p>
  
  <p>Can anybody help me in doing this?</p>
  
  <p>Thanks</p>