Importing and transforming multiple instruments

Importing and Managing Financial Data in R

Joshua Ulrich

Quantitative Analyst & quantmod Co-Author and Maintainer

Download instruments into a custom environment

# Create new environment
data_env <- new.env()

# Use getSymbols to load data into the environment
getSymbols(c("SPY", "QQQ"), env = data_env, auto.assign = TRUE)

"SPY" "QQQ"

# Look at a few rows of the SPY data
head(data_env$SPY, 3)

            SPY.Open SPY.High SPY.Low SPY.Close SPY.Volume SPY.Adjusted
 2007-01-03   142.25   142.86  140.57    141.37   94807600     114.8094
 2007-01-04   141.23   142.05  140.61    141.67   69620600     115.0530
 2007-01-05   141.33   141.40  140.38    140.54   76645300     114.1353

Using lapply()

Loops over all objects in environment
Combine list of function results into one object using do.call()
- First argument (what) is the function to be called
- Second argument (args) is a list of arguments to pass

Extract volume and merge into one object

# Extract volume column from each object
adjusted_list <- lapply(data_env, Ad)

# Merge each list element into one object
adjusted <- do.call(merge, adjusted_list)

head(adjusted)

            QQQ.Adjusted SPY.Adjusted
 2007-01-03     39.47694     114.8094
 2007-01-04     40.22558     115.0530
 2007-01-05     40.03385     114.1353
 2007-01-08     40.06124     114.6632
 2007-01-09     40.26210     114.5658
 2007-01-10     40.73684     114.9475

Let's practice!

Importing and Managing Financial Data in R