Julian Hillebrand
Hey everybody,
today I show you how you can start working with the Google+ API to analyze Google+ posts with R. We create a personal API key, get our own stats and plot them in a nice looking graph.
Get the API Key
You can get our API key on the Google Developer console here: https://code.google.com/apis/console
There you can see an overview of you API activities if you have some. To create a new API connection click on “APIs” and turn on the Google+ API.
After you did this, you can click on “Google+” and you see a list of the available API calls. Now click on “Credentials” on the left and click on “Create new key” to create a new public API access. Then click on “Browser key” and then “Create”.
And there it is: you API key.
Analyze Google+ Posts with R
For our first analysis we need the packages
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library(RCurl); library(RJSONIO); |
And we need our api key and our user id:
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api_key<-"XXX" user_id <- "105616015219357887822" |
In this case I used my own Google+ ID but you can use every ID you want. But we can just receive the public posts.
We get our raw data and put it in a JSON object with:
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data <- getURL(paste("https://www.googleapis.com/plus/v1/people/",user_id,"/activities/public?maxResults=100&key=", api_key, sep=""),ssl.verifypeer = FALSE) js <- fromJSON(data, asText=TRUE); |
We can now put the data in a DataFrame to make it more readable. But we don´t need all the values we received as these are a lot. We get the fields
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df = data.frame(no = 1:length(js$items)) for (i in 1:nrow(df)){ df$kind[i] = js$items[[i]]$verb df$title[i] = js$items[[i]]$title df$replies[i] = js$items[[i]]$object$replies$totalItems df$plusones[i] = js$items[[i]]$object$plusoners$totalItems df$reshares[i] = js$items[[i]]$object$resharers$totalItems df$url[i] = js$items[[i]]$object$url } |
We can save this DataFrame as a CSV file with:
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filename <- paste("gplus_data_", user_id, sep="") # in case we have more user_ids write.table(df, file = paste0(filename,".csv"), sep = ",", col.names = NA, qmethod = "double") |
Visualize your Posts
To visualize your posts we extract the informations we need and store them in the Data Frame df_graph
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df_graph = df[,c(1,4,5,6)] |
Then we can plot it with
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require(ggplot2) require(reshape2) melted=melt(df_graph,id.vars='no') ggplot(melted,aes(x=factor(no),y=value,color=factor(variable),group=factor(variable)))+ geom_line()+xlab('no')+guides(color=guide_legend("metrics"))+ labs(title="Google+") |
You can find the complete code on my github page here.
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Daniel Boller
