Two arguments x and y can be merged by interleaving their items (necessarily of a common shape) as determined by a Boolean list of shape x + y. For example: |
x=: >;:'That they hunted from hill'
y=: >;:'second time me to plain'
b=: 0 1 1 0 0 1 0 0 1 1
mrg=: 1 : '/:@/:@(x."_) { ,'
x([ ; ] ; (,.b)"_ ; b mrg)y
+----------------------+
¦That ¦second¦0¦That ¦
¦they ¦time ¦1¦second¦
¦hunted¦me ¦1¦time ¦
¦from ¦to ¦0¦they ¦
¦hill ¦plain ¦0¦hunted¦
¦ ¦ ¦1¦me ¦
¦ ¦ ¦0¦from ¦
¦ ¦ ¦0¦hill ¦
¦ ¦ ¦1¦to ¦
¦ ¦ ¦1¦plain ¦
+----------------------+
The form of the function b mrg obtained by applying the adverb mrg suggests the form of a function MRG to be applied to a Boolean left argument and a right argument formed as the catenation of the original arguments. Thus: |
b mrg
/:@/:@(0 1 1 0 0 1 0 0 1 1"_) { ,
MRG=: /:@/:@[ { ]
b MRG x,y
That
second
time
they
hunted
me
from
hill
to
plain
The argument b need not be Boolean, but may be anything of the requisite number of items that is in the domain of /:. For example: |
b=: 0 2 2 1 0 2 2 2 0 0 1 1 2 1 2 1 1 1 1 1
y0=: 'abcd' [ y1=: '123456789' [ y2=: 'zzzzzzz'
b MRG y0,y1,y2
azz1bzzzcd23z4z56789
a0=: mrg=: 1 : '/:@/:@(x."_) { ,' | x b mrg y merges x and y |
m1=: MRG=: /:@/:@[ { ] | b MRG x,y is equivalent to above |
d2=: alt=: ,@,. M | erge items from x and y alternately |
For example:
|
x=: 'temr rtes'
y=: 'h axbohr '
x alt y
the marx brothers
An argument can be amended by replacing those cells selected by an index, by the cells of another argument. For example: |
x=: 'ABCD' [ y=: 'abcdefghij'
i=: 4 2 8 6
i{y
ecig
]z=: x i} y
abBdAfDhCj
m=: a.{~(a. i. 'A')+i.5 5
]i=: 2 # &.> i. # m
+-------------------+
¦0 0¦1 1¦2 2¦3 3¦4 4¦
+-------------------+
x=: '+-*%^'
m ; (i{m) ; x ; x i} m
+-----------------------+
¦ABCDE¦AGMSY¦+-*%^¦+BCDE¦
¦FGHIJ¦ ¦ ¦F-HIJ¦
¦KLMNO¦ ¦ ¦KL*NO¦
¦PQRST¦ ¦ ¦PQR%T¦
¦UVWXY¦ ¦ ¦UVWX^¦
+-----------------------+
Amendment can also be made by using a function that selects a portion of its argument. For example: |
IR=: @(i.@$@]) Adverb to select indices of (ravelled) table right argument
A=: IR } Adverb to amend selected portion of right argument
d=: (<0 1)&|: Function to select diagonal of a table
'+-*%^' (] ; d@] ; ]IR ; d IR ; d IR } ; d A) m
+---------------------------------------------------+
¦ABCDE¦AGMSY¦ 0 1 2 3 4¦0 6 12 18 24¦+BCDE¦+BCDE¦
¦FGHIJ¦ ¦ 5 6 7 8 9¦ ¦F-HIJ¦F-HIJ¦
¦KLMNO¦ ¦10 11 12 13 14¦ ¦KL*NO¦KL*NO¦
¦PQRST¦ ¦15 16 17 18 19¦ ¦PQR%T¦PQR%T¦
¦UVWXY¦ ¦20 21 22 23 24¦ ¦UVWX^¦UVWX^¦
+---------------------------------------------------+
m diag m Indices of ravelled m Indices of diagonal Amendments
ur=: 2 _3&{. Select upper right corner
(2 3$'+-*%^!') (] ; ur@] ; ]IR ; ur IR ; ur IR } ; ur A) m
+------------------------------------------+
¦ABCDE¦CDE¦ 0 1 2 3 4¦2 3 4¦AB+-*¦AB+-*¦
¦FGHIJ¦HIJ¦ 5 6 7 8 9¦7 8 9¦FG%^!¦FG%^!¦
¦KLMNO¦ ¦10 11 12 13 14¦ ¦KLMNO¦KLMNO¦
¦PQRST¦ ¦15 16 17 18 19¦ ¦PQRST¦PQRST¦
¦UVWXY¦ ¦20 21 22 23 24¦ ¦UVWXY¦UVWXY¦
+------------------------------------------+
a3=: IR=: @(i.@$@]) | f IR selects indices of ravelled rgt arg |
m4=: d=: (<0 1)&|: | Function to select diagonal of table |
m5=: ur=: 2 _3&{. | Function to select upper right corner |
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