- 1 general/misc
- 1.1 'guid'
- 1.2 'numeric'
- 1.3 'pack'
- 1.4 'parts'
- 1.5 'trace'
- 1.6 'validate'
- 1.7 'general/misc/*'
Before using these scripts you will need to ensure they have been installed. This can be done on a connected machine through J's package manager, or from the command line:
load 'pacman' 'install' jpkg 'general/misc'
If you are working offline and need to install these scripts you will need to obtain a copy of an archive containing them and unpack it in J's addons directory.
You can find the absolute location of these scripts using jpath. For example, on windows, you might get behavior like this:
jpath '~addons/general/misc/prompt' c:/users/username/j64-803/addons/general/misc/prompt
Usually, require is sufficient to use any of these scripts within a session, for example:
require 'numeric validate' 1 (],roundbanker,:rounddist) 0.1*?10#100 9.4 8.2 3.5 7.9 9 2.3 8.1 5.2 6.7 3.4 9 8 4 8 9 2 8 5 7 3 9 9 3 8 9 2 8 6 6 4 ismatrix 1 (],roundbanker,:rounddist) 0.1*?10#100 1
If open and edit are defined in your session, they can be useful for inspecting the code. For example:
open 'general/misc/jdll' edit 'roundbanker'
If edit is not defined but open is, you could use, for example:
... and then search for the definition of roundbanker within that file. (This lets you read the comments on the code, if there are any.)
May also be referred to as 'general/misc/guid'
Create guids in various formats
All guid verbs take the prefix of the shape of guids to return, eg
require 'general/misc/guid' $guids $0 NB. create guid as a 16-byte character string 16 $guids 2 3 NB. create 2x3 array of 16-byte strings 2 3 16
guids return guids as 16-byte strings guidsn return guids as 24-character file names guidsr return guids as 36-character strings, without braces guidss return guids as 38-character strings, with braces guidsx return guids as extended precision integers
May also be referred to as 'general/misc/numeric'
Various numeric utilities
baserep y in base x clean clean y to tolerance of x (default 1e_10) colsum sum data columns of matrix by key groupndx group indices of y in x int01 interval in n steps from 0 to 1 (= steps 0 1,n) linsert linear insert x (default 2) steps into y randomize sets a random value into random link range range from a to b [in steps of c] recur solves recurrence r(i)=a(i)+r(i-1)*m(i-1) round round y to nearest x (e.g. 1000 round 12345) roundbanker round y to nearest x with bankers rounding rounddist round y to nearest x preserving total rounddown round y down to nearest x roundint round to nearest integer roundup round y up to nearest x steps steps from a to b in c steps
May also be referred to as 'general/misc/pack'
a package is a 2-column matrix of: name, value that can be used to store nouns, or otherwise associate names and values.
A name is any character vector. pack and pdef work only when the names are proper J names.
definitions for nouns only:
pk=. pack nl create package from namelist nl=. pdef pk define package
definitions for any names:
text=. pk1 pcompare pk2 compare packages val=. name pget pk get value of name in package pk=. new pset old merge new and old packages pk=. nl pex pk remove namelist from package pk=. nl psel pk select namelist from package res=. packlocale locs package all nouns in locales
May also be referred to as 'general/misc/parts'
Partitions are typically given by a boolean with 1's marking the beginning or end of each partition. Partitions are also sometimes given in terms of the lengths of each partition.
Verbs defined here assume that boolean 1's mark the beginning of each partition - see comments at the end for examples of end-partition verbs.
The verbs psum and psumscan illustrate definitions appropriate for verbs that return scalar or non-scalar results, respectively. utility used to build non-scalar partition functions:
require 'general/misc/parts' firstones 1 1 0 1 1 1 0 1 0 0 1 0 0 0 lastones 1 1 1 0 1 0 0 1 0 1 lfp 1 0 1 0 0 1 2 3 1 partition 1 9 9 4 4 4 9 1 1 0 1 0 0 1 runindices 3 1 2 1 0 0 0 1 2 2 3 runlengths 1 9 9 4 4 4 9 1 2 3 1 x=: 1 0 1 0 0 y=: 5 3 2 2 7 x preverse y 3 5 7 2 2 x psort y 3 5 2 2 7 x psum y 8 11 x psumscan y 5 8 2 4 11
May also be referred to as 'general/misc/trace'
Execution trace utilities
The main functions are "trace" and "paren".
x trace y trace sentence y to x levels of function calls trace y same as _ trace y
require 'trace' trace '3+i.4' --------------- 1 Monad ------ i. 4 0 1 2 3 --------------- 2 Dyad ------- 3 + 0 1 2 3 3 4 5 6 ============================== 3 4 5 6
Tracing provides information on results within a line; the action labels 0 monad, 1 monad, 9 paren, etc., are from the parse table in Section II.E of the J dictionary.
paren y fully parenthesize sentence y
require 'trace' paren '+/i.4' ((+/)(i.4)) paren '(3 4$i.12)+/ .**:i.4' ((3 4$(i.12))((+/) .*)(*:(i.4)))
See also: Scripts/Tracer
May also be referred to as 'general/misc/validate'
Data validation functions
verbs return 1 if true, 0 if false
data type verbs check the data, not the internal representation. For example, 1j1-0j1 is considered boolean, though stored as complex.
require 'general/misc/validate' 5 10 inrange i.12 '()' isbalanced '(123(45))'
The provided verbs are:
inrange (low, high) inrange data isbalanced pair isbalanced string isboolean data is all 0 or 1 isboxed is boxed ischaracter data is character iscounter data is non-negative integer (counting number) iscomplex data is complex isdate is date (as yyyy mm dd) isempty data is empty isinteger data is all integer ismatrix data is a matrix isnumeric data is numeric isrational data is rational isreal data is all real isscalar data is a scalar isunicode data is unicode isunique data has no duplicates isutf8 text is valid UTF-8 isvector data is a vector
These scripts do not have short aliases.
So, for example, require 'general/misc/format general/misc/prompt' but not: require 'format prompt'
Handle files larger than 2^31 bytes (for 32 bit windows).
microsoft windows specific alternative to wd'clippaste'.
Supposedly support for beginners to write code in "a more literate style".
Needs considerably more documentation (book(s), lab(s), tutorial(s), etc...) for this approach to be accessible to beginners. So far, all we have is Guides/Primitives
This script allows you to see how hooks, forks, and other structural elements affect the order of processing verbs.
First, select the kind of display you want with 'setfnform'.
The operands are 'math' (display like f(x,y)), 'J' (display like x f y), and 'Jv' (like J, but monads are followed by '_' and dyads are preceded and followed by '_'). Example:
require 'general/misc/fndisplay' setfnform 'math'
Then, define the verb-names you want to use: defverbs 'f g h'
Finally, define any names you want to use for nouns: defnouns 'x y'
Then, entering combinations of your verbs and nouns will show you how the combinations will be executed.
By default a verb has infinite rank; you can append "r to a verb-name in defverbs to assign the rank r to the verb.
x f&.g y +----------------+ |g`(f(g(x),g(y)))| +----------------+
where g means the inverse of g.
Utilities to manipulate font family names.
This is similar to http://www.w3.org/TR/CSS21/fonts.html but not quite the same.
center width center text clipfmt format data for clipboard clipunfmt unformat data read from clipboard colhdr column headers expandby expand data with fit value expandn expand data at every nth item flatten flatten array to a character string fold fold text to width hexdump show text as hex and ascii characters nfmt simple numeric formatter ruler returns formatted ruler sqzint squeeze list of positive integers into short form sqzrun squeeze list of numbers into short form xfmt format extended integers
This script gives examples of calling the J DLL from J. Similar routines may be written in other languages that can call DLLs.
The internal representation used is that for intel machines.
jclear clear J session jcmd send sentence, return result jdo send sentence to be executed jget retrieve value of J noun jset assign value to J noun
jinit initialize J instance jfree free J instance
Loading the script initializes a J instance, defining global pJ as the handle. Use jfree to free it.
See examples at the end of the script itself, and http://www.jsoftware.com/help/dictionary/dx003.htm
http://www.jsoftware.com/docs/help602/user/script_dll.htm might also be of historical interest.
prompts for input, optionally with a default result
form: [default] prompt prompt_text
require 'general/misc/prompt' prompt 'start date: ' '2001 5 23' prompt 'start date: '
. - the default is only available in JQt . - this will not work in a script . - in Windows console a newline is added after the prompt