beaver 🦫

A common lisp library for data analysis and manipulation. Modelled after the pandas library

• Walkthrough
• Reference
  • IO
  • Transformations
  • Columns
  • Sorting

Walkthrough

Let's analyze some bitcoin data, start by modifying main.lisp

(load "./src/beaver.lisp")

(defvar data (beaver:read-csv "./data/btc.csv"))

(print data) ;; Let's go!

Well, let's first remove some columns to simplify our data

(load "./src/beaver.lisp")

(defvar data (beaver:read-csv "./data/btc.csv"))

(print (beaver:drop-column data '("Symbol" "Data" "Open" "Close" "Volume" "Name" "SNo")))

(("Date" "High" "Low" "Marketcap")
 ("2013-04-29 23:59:59" "147.48800659179688" "134.0" "1603768864.5")
 ("2013-04-30 23:59:59" "146.92999267578125" "134.0500030517578"
  "1542813125.0")...

Now, let's sort the data by the maximum marketcap

(load "./src/beaver.lisp")

(defvar data (beaver:read-csv "./data/btc.csv"))

(print (beaver:sort-by data "Marketcap"))

(("SNo" "Name" "Symbol" "Date" "High" "Low" "Open" "Close" "Volume"
  "Marketcap")
 ("68" "Bitcoin" "BTC" "2013-07-05 23:59:59" "80.0" "65.5260009765625"
  "79.98999786376953" "68.43099975585938" "0.0" "778411178.875")
 ("69" "Bitcoin" "BTC" "2013-07-06 23:59:59" "75.0" "66.81999969482422"
  "68.50499725341797" "70.27729797363281" "0.0" "799741618.54")...

Next let's check the mean of the High cap

(load "./src/beaver.lisp")

(defvar data (beaver:read-csv "./data/btc.csv"))

(print (float
        (beaver:get-mean
         (beaver:get-column data "High"))
        ))

6893.326 

Reference

IO

(read-csv "./data/btc.csv" ",")

Read a CSV into a 2d matrix, accepts an optional delimiter

(write-csv matrix "./output.csv" ",")

Write a 2d matrix into a CSV accepts an optional delimiter

Transformations

(beaver:transpose matrix)

Transforms the top most row into a column

(beaver:melt matrix '("Col1" "Col2" "Col3") '("Cols" "Types"))

"Melts" or reduce N amount of columns into two columns

Columns

(beaver:get-column matrix "Col1")

Returns the specified columns, if Col1 is not provided it will the top-most row

(beaver:drop-column '("Col1" "Col2"))

Returns a new matrix with the removed columns

(beaver:set-column matrix "Col1" '("Foo" "Bar" "Baz"))

Returns the updated matrix with Col1 replaced with Col2 and it's data

Sorting

(beaver:sort-by matrix "Col1")

Performs a simple numerical sorts and returns the a new, updated matrix

Credits

• BTC pricing data
• Surveymonkey data