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POPlot point text labels over polygon w/o overlap
 

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  1. POPlot point text labels over polygon w/o overlap
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    <p>Using pointLabel in the maptools package in R will plot text labels for points to avoid overlap of text. </p> <p>But is there a way to avoid/minimize overlap of text labels with the outline of an underlying polygon created from a shape file? </p> <p>For example, when plotting location of census blocks, one would like the text labels not to fall on top of nearby census block borders, etc. </p> <p>The data I am using was acquired from the 2000 Census Blocks Version 12A located at: <a href="http://www.nyc.gov/html/dcp/download/bytes/nycd_12aav.zip" rel="nofollow">http://www.nyc.gov/html/dcp/download/bytes/nycd_12aav.zip</a></p> <p>and unpacks to the following 5 files: </p> <pre><code>nycd.dbf nycd.prj nycd.shp nycd.shp.xml nycd.shx </code></pre> <p>I intended to label the various blocks from my own text file that contains the vertical list:</p> <pre><code>Zone 1 Zone 2 Zone 3 Zone 4 etc. </code></pre> <p>I loaded the following libraries:</p> <pre><code>library(gpclib) library(maptools) library(RColorBrewer) library(classInt) library(maps) </code></pre> <p>I then tried:</p> <pre><code>zip=readShapePoly(file.choose()) </code></pre> <p>and selected the <code>nycd.shp</code> file above. Then:</p> <pre><code>plot(zip, col="lightgray", border="black", axes=TRUE, pbg="white") </code></pre> <p>And if it won't cause other conflicts with the labeling, I would prefer to color it:</p> <pre><code>zip@data$noise &lt;- rnorm(nrow(zip@data)) colors=brewer.pal(9, "YlOrRd") cols[is.na(cols)] &lt;- "#D9D9D9" brks=classIntervals(zip$noise, n=9, style="quantile")$brks plot(zip, col=colors[findInterval(zip$noise, brks,all.inside=TRUE)], axes=F) </code></pre> <p>How would I label the various regions by Zone 1, Zone 2 etc, without/minimizing the label from extending outside each polygon? My questions implies I know how to label shape files with text. I don't know how to label shapes with words, only points with their xy value, or as an expression like alpha/beta with <code>pointLabel</code>. I can figure out some functionality with the <code>maps</code> tool if the text is contained within the original file and can therefore be accessed with a <code>$name</code> extension. Similar to code I saw from <a href="http://geography.uoregon.edu/GeogR/examples/maps_examples02.htm" rel="nofollow">http://geography.uoregon.edu/GeogR/examples/maps_examples02.htm</a>:</p> <pre><code># map of large cities data(world.cities) # make the world cities location data set from the maps package available # match the large cities with those in the database m &lt;- match(paste(tolower(as.character(cities$City)),tolower(as.character(cities$Country))), paste(tolower(world.cities$name),tolower(world.cities$country.etc))) # assign the world.cities location information to the large cities big.cities &lt;- NULL big.cities$name &lt;- cities2$City big.cities$long &lt;- world.cities$long[m] big.cities$lat &lt;- world.cities$lat[m] big.cities # plot the map map("world") map.axes() points(big.cities$long,big.cities$lat, col="blue") text(big.cities$long, big.cities$lat, big.cities$name, col="red", cex=.5 </code></pre> <p>But unfortunately this is not a solution for me as there is no <code>$name</code> extension with the labels I would like to use. All I can say is that I didn't post until I went through this site with the internal search, and the last few days online googling. From what I have seen is that this site and this community helps beginners [relative to the very advanced skills of the people on here] like me. </p> <p>Thank you in advance.</p>
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    1. USchrki
    1. USAaron
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      1. POPlot point text labels over polygon w/o overlap
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      1. VTUpMod
    1. COSome of us have gotten tired of guessing at what sort of data people might be working with. Search SO for "great reproducible example".
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      1. US42-
    2. COplease show us what have you tried at least
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      1. USmamdouh alramadan
    3. COOk. I'm on it. Thanks.
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      1. USAaron
 

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