NB. A table is a list of columns NB. A column is a 2 element list of boxes. NB. The first box contains the column name NB. The second box contains the column data (a list)

NB. Creation tabulate x:boxed list of column names y:boxed list of corresponding column values

NB. Metadata colNames y:table

colData y:table

count y:table

colIdx x:table y:boxed column name

NB. Query selCol x:table y:boxed column name

selIdxs x:table y:indices

valCol x:table y:boxed column name

NB. Append append x:table y:boxed lists corresponding to the schema of the table, to be appended to the end

appendTable x:table y:table with the same schema

NB. Helper t_arg y:table boxed with a column name ie mytable;'mycol'

col_arg y:table boxed with a column name

NB. Transform transValCol u:monadic, rank-preserving function y:table boxed with a column name

transCol u:monadic, rank-preserving function y:table boxed with a column name

NB. Delete delCol x:table y:boxed column name

delIdxs x:table y:indices

delColIdxs x:table y:indices of the columns within the schema

NB. Filter where u:monadic, boolean-returning function y:table boxed with a column name

filter u:monadic, boolean-returning function y:table boxed with a column name

dfilter u:monadic, boolean-returning function y:table boxed with a column name

NB. Update updIdxs x:table y:boxed list of column name, indices to replace and their replacements ie 'mycol';indices;replacements

NB. Presentation columnate y:list

show y:table

NB. Lib system y:string to be sent to the operating system for execution

type y:j object. 1=bool, 2=char, 4=integer, 8=float

read y:boxed absolute file path

getenv y:string for environment variable

iread y:boxed list of an absolute file path and a 2 element list of an offset and a number of bytes to read

split x:delimiter y:string

filesize y:boxed absolute file path

apply x:string containing a named monadic function y:arg

readDsv x:boxed list of delimiter, column names and column types, where S=string, N=number, X=ignore y:absolute file path

To see readDsv in action, type the following after cloning into your ~/j64-{version}-user/projects/ folder:

projects_home=:> (<1 1){UserFolders_j_
load projects_home,'/jtables/lib.ijs'
t=:(';';('time';'open';'high';'low';'close';'zeroes');'SNNNNX') readCsv (projects_home,'/jtables/test.csv')
t=:formatDatetime1 transCol t;'datetime'
show t
count t
meanOpen=:(+/ % #) transValCol t;'open'
show (>&meanOpen) filter t;'open'