Be advised that the analysis takes several weeks of computing time and upwards of 50 GB of available RAM to execute.
### Prerequisites
The main analysis is done with the R statistical programming language. R itself can be downloaded [here](https://cloud.r-project.org/). [RStudio](https://www.rstudio.com/products/rstudio/download/#download) is a good IDE for R. Install the necessary R packages with:
```R
install.packages("rbch")
install.packages("data.table")
install.packages("future.apply")
```
You must have a Bitcoin Cash (BCH) full node synced with the transaction index enabled with the `-txindex` flag. As of now, the analysis has been tested with the [Bitcoin Unlimited](https://www.bitcoinunlimited.info/) node implementation.
### `extract-tx-graphs.R`
The [R/extract-tx-graphs.R](R/extract-tx-graphs.R) script file issues JSON-RPC queries to `bitcoind`, the Bitcoin Cash node daemon. Make sure `bitcoind` is running before initiating this script.
In the R script file you must set `bitcoin.conf.file` to the filepath of your bitcoin.conf file and `data.dir` to the directory where you want files to be stored.
The script spawns multiple R process threads to accelerate queries to `bitcoind` and will take several hours to execute. In the specified data directory, a set of files named `tx_graph_height_BEGIN _to_END.rds` will be created.
The R object format of these files is:
```
List of 2
$ incoming: Classes 'data.table and 'data.frame': N obs. of 3 variables:
..$ txid : chr [txid of the transaction]
..$ origin.txid : chr [txid of the output that is being spent by the transaction]
..$ origin.position : num [the position (of the output being spent) within the output's transaction, indexed from one]
$ outgoing: Classes 'data.table and 'data.frame': N obs. of 4 variables:
..$ txid : chr [txid of the transaction]
..$ address : chr [address that the transaction is being spent to]
..$ position : int [position of the output being produced by the transaction, indexed from one]
..$ value : num [quantity of BCH being spent to each address]
```
Note that, unlike the underlying blockchain data, the position of outputs is indexed from one, not from zero.
