[R-SIG-Finance] Getting started with blotter (adding transactions)

[Bos, Roger]

All,

I am trying to learn how to use the blotter package.  I would eventually like to use it to calculate the P&L of a small portfolio.  In my (hopefully) reproducible example below it allows me to add the first transaction, but not the second.
I also get a warning that the instrument is not found.  Could someone point me in the right direction here?  If I have overlooked a good tutorial on this, please let me know that as well.  Here is the error message I get:

> # Add some transactions
> addTxn(portfolio, Symbol='EWJ',  TxnDate='2015-05-13', TxnPrice=30.51, TxnQty = 328, TxnFees=0, verbose=TRUE)
[1] "2015-05-13 00:00:00 EWJ 328 @ 30.51"
Warning messages:
1: In getInstrument(Symbol) :
  instrument EWJ not found, please create it first.
2: In addTxn(portfolio, Symbol = "EWJ", TxnDate = "2015-05-13", TxnPrice = 30.51,  :
  Instrument EWJ  not found, using contract multiplier of 1
> addTxn(portfolio, Symbol='EWJ',  TxnDate='2015-05-15', TxnPrice=31.51, TxnQty = -328, TxnFees=0, verbose=TRUE)
Error in last(PosData[which(index(PosData) <= Date), ][, Columns], n = n) :
  unused argument (n = n)
>

****

require(xts)
require(quantmod)
require(blotter)

Sys.setenv(TZ="EST")

# xts object must be created with explicit index class:
initDate <- '2000-01-01'
getSymbols('SPY', from=initDate, index.class=c("POSIXt","POSIXct"))

portfolio <- "bos"
account <- "acct"
initEq <- 0

# When the test is conducted all blotter related values are written into .blotter environment. If you want repeat the same test, then you need to get rid of all .blotter values. So, you have to run something like this:
rm(list=ls(envir=.blotter), envir = .blotter)

# Add some symbols
sym <- c("EWJ","EWI")
initPortf(name=portfolio, sym, initDate = initDate)
initAcct(account,portfolios=c(portfolio), initDate = initDate, initEq = initEq)

# Add some transactions
addTxn(portfolio, Symbol='EWJ',  TxnDate='2015-05-13', TxnPrice=30.51, TxnQty = 328, TxnFees=0, verbose=TRUE)
addTxn(portfolio, Symbol='EWJ',  TxnDate='2015-05-15', TxnPrice=31.51, TxnQty = -328, TxnFees=0, verbose=TRUE)




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