ggplot mapping fill based on two different conditions
<p>I'd like to make a map where the states are colored according to one criteria, and crosshatched (or somehow otherwise differentiated) according to a different criteria. So far what I have is</p>

<pre><code>library(ggmap)
library(mapdata)
library(ggplot2)
library(dplyr)
region&lt;-c("california","nevada","oregon","washington")
var1&lt;-c(0,1,0,1)
var2&lt;-c(3,4,4,3)
my_data&lt;-data.frame(region, var1, var2)
all_states_map &lt;- map_data("state")
Total &lt;- inner_join(all_states_map,my_data, by = "region")
Total$var1&lt;-as.factor(Total$var1)
my_map &lt;- ggplot() + geom_polygon(data=Total, aes(x=long, y=lat, group = Total$group, fill=Total$var1),colour="white",
                         show.legend=TRUE) + scale_fill_manual(values=c("blue","gray"))
</code></pre>

<p>So now my states are color coded based on whether var1 is 0 or 1. Is there a way to overlay something on top of that to crosshatch states where var2 is 3, and leave alone the states where var2 is 4?</p>

<p>Edit: what I'd like is something like this:<a href="https://i.stack.imgur.com/EEUz8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EEUz8.png" alt="my map"></a></p>