How to invert MapIndexed on a ragged structure? How to construct a tree from rules? The Next CEO of Stack OverflowFrom a list to a list of rulesHow to partition a list according to a nested table structure?Visualize a tree structure using TreeGraphExplore a nested listDrop selection of columns from a ragged arrayHow to check if two nested lists have the same structure?Rule-based branching construction of listsHow to convert a tree in a list?Replacement Rule for “flattening” list whilst adding attributesRagged Transpose
What expression will give age in years in QGIS?
Skipping indices in a product
How to solve a differential equation with a term to a power?
Bold, vivid family
Is it my responsibility to learn a new technology in my own time my employer wants to implement?
Why do professional authors make "consistency" mistakes? And how to avoid them?
MessageLevel in QGIS3
Why do we use the plural of movies in this phrase "We went to the movies last night."?
multiple labels for a single equation
Why am I allowed to create multiple unique pointers from a single object?
How do scammers retract money, while you can’t?
Why don't programming languages automatically manage the synchronous/asynchronous problem?
How to add tiny 0.5A 120V load to very remote split phase 240v 3 wire well house
Is there an analogue of projective spaces for proper schemes?
Can you replace a racial trait cantrip when leveling up?
How to invert MapIndexed on a ragged structure? How to construct a tree from rules?
Sending manuscript to multiple publishers
Are there any limitations on attacking while grappling?
Why does standard notation not preserve intervals (visually)
Example of a Mathematician/Physicist whose Other Publications during their PhD eclipsed their PhD Thesis
What flight has the highest ratio of time difference to flight time?
Indicator light circuit
Interfacing a button to MCU (and PC) with 50m long cable
Is it possible to search for a directory/file combination?
How to invert MapIndexed on a ragged structure? How to construct a tree from rules?
The Next CEO of Stack OverflowFrom a list to a list of rulesHow to partition a list according to a nested table structure?Visualize a tree structure using TreeGraphExplore a nested listDrop selection of columns from a ragged arrayHow to check if two nested lists have the same structure?Rule-based branching construction of listsHow to convert a tree in a list?Replacement Rule for “flattening” list whilst adding attributesRagged Transpose
$begingroup$
I have an arbitrary ragged nested list-of-lists (a tree) like
A = a, b, c, d, e, f, g, h, i, j, k, l, m, n;
Its structure is given by the rules
B = Flatten[MapIndexed[#2 -> #1 &, A, -1]]
1, 1 -> a, 1, 2 -> b, 2, 1 -> c, 2, 2 -> d, 3, 1, 1, 1 -> e, 3, 1, 1, 2 -> f, 3, 1, 1, 3 -> g, 3, 1, 1, 4 -> h, 3, 1, 1, 5 -> i, 3, 1, 2, 1 -> j, 3, 1, 2, 2 -> k, 3, 1, 2, 3 -> l, 3, 2 -> m, 4 -> n
How can I invert this operation? How can I construct A
solely from the information given in B
?
list-manipulation data-structures trees
$endgroup$
add a comment |
$begingroup$
I have an arbitrary ragged nested list-of-lists (a tree) like
A = a, b, c, d, e, f, g, h, i, j, k, l, m, n;
Its structure is given by the rules
B = Flatten[MapIndexed[#2 -> #1 &, A, -1]]
1, 1 -> a, 1, 2 -> b, 2, 1 -> c, 2, 2 -> d, 3, 1, 1, 1 -> e, 3, 1, 1, 2 -> f, 3, 1, 1, 3 -> g, 3, 1, 1, 4 -> h, 3, 1, 1, 5 -> i, 3, 1, 2, 1 -> j, 3, 1, 2, 2 -> k, 3, 1, 2, 3 -> l, 3, 2 -> m, 4 -> n
How can I invert this operation? How can I construct A
solely from the information given in B
?
list-manipulation data-structures trees
$endgroup$
add a comment |
$begingroup$
I have an arbitrary ragged nested list-of-lists (a tree) like
A = a, b, c, d, e, f, g, h, i, j, k, l, m, n;
Its structure is given by the rules
B = Flatten[MapIndexed[#2 -> #1 &, A, -1]]
1, 1 -> a, 1, 2 -> b, 2, 1 -> c, 2, 2 -> d, 3, 1, 1, 1 -> e, 3, 1, 1, 2 -> f, 3, 1, 1, 3 -> g, 3, 1, 1, 4 -> h, 3, 1, 1, 5 -> i, 3, 1, 2, 1 -> j, 3, 1, 2, 2 -> k, 3, 1, 2, 3 -> l, 3, 2 -> m, 4 -> n
How can I invert this operation? How can I construct A
solely from the information given in B
?
list-manipulation data-structures trees
$endgroup$
I have an arbitrary ragged nested list-of-lists (a tree) like
A = a, b, c, d, e, f, g, h, i, j, k, l, m, n;
Its structure is given by the rules
B = Flatten[MapIndexed[#2 -> #1 &, A, -1]]
1, 1 -> a, 1, 2 -> b, 2, 1 -> c, 2, 2 -> d, 3, 1, 1, 1 -> e, 3, 1, 1, 2 -> f, 3, 1, 1, 3 -> g, 3, 1, 1, 4 -> h, 3, 1, 1, 5 -> i, 3, 1, 2, 1 -> j, 3, 1, 2, 2 -> k, 3, 1, 2, 3 -> l, 3, 2 -> m, 4 -> n
How can I invert this operation? How can I construct A
solely from the information given in B
?
list-manipulation data-structures trees
list-manipulation data-structures trees
asked 3 hours ago
RomanRoman
3,9661022
3,9661022
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
$begingroup$
Here's a procedural way:
Block[
Nothing,
Module[
m = Max[Length /@ Keys[B]], arr,
arr = ConstantArray[Nothing, Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]];
Map[Function[arr[[Sequence @@ #[[1]]]] = #[[2]]], B];
arr
]
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's an inefficient but reasonably simple way:
groupMe[rules_] :=
If[Head[rules[[1]]] === Rule,
Values@GroupBy[
rules,
(#[[1, 1]] &) ->
(If[Length[#[[1]]] === 1, #[[2]], #[[1, 2 ;;]] -> #[[2]]] &),
groupMe
],
rules[[1]]
]
groupMe[B]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's a convoluted way using pattern replacements:
DeleteCases[
With[m = Max[Length /@ Keys[B]],
Array[
List,
Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]
] /.
Map[
Fold[
Insert[
#, ___,
_,
Append[ConstantArray[1, #2], -1]] &,
#[[1]],
Range[m - Length[#[[1]]]]
] -> #[[2]] &,
B
]
],
__Integer,
Infinity
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "387"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e)
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom))
StackExchange.using('gps', function() StackExchange.gps.track('embedded_signup_form.view', location: 'question_page' ); );
$window.unbind('scroll', onScroll);
;
$window.on('scroll', onScroll);
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f194217%2fhow-to-invert-mapindexed-on-a-ragged-structure-how-to-construct-a-tree-from-rul%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Here's a procedural way:
Block[
Nothing,
Module[
m = Max[Length /@ Keys[B]], arr,
arr = ConstantArray[Nothing, Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]];
Map[Function[arr[[Sequence @@ #[[1]]]] = #[[2]]], B];
arr
]
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's a procedural way:
Block[
Nothing,
Module[
m = Max[Length /@ Keys[B]], arr,
arr = ConstantArray[Nothing, Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]];
Map[Function[arr[[Sequence @@ #[[1]]]] = #[[2]]], B];
arr
]
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's a procedural way:
Block[
Nothing,
Module[
m = Max[Length /@ Keys[B]], arr,
arr = ConstantArray[Nothing, Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]];
Map[Function[arr[[Sequence @@ #[[1]]]] = #[[2]]], B];
arr
]
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
Here's a procedural way:
Block[
Nothing,
Module[
m = Max[Length /@ Keys[B]], arr,
arr = ConstantArray[Nothing, Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]];
Map[Function[arr[[Sequence @@ #[[1]]]] = #[[2]]], B];
arr
]
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
answered 2 hours ago
b3m2a1b3m2a1
28.3k358163
28.3k358163
add a comment |
add a comment |
$begingroup$
Here's an inefficient but reasonably simple way:
groupMe[rules_] :=
If[Head[rules[[1]]] === Rule,
Values@GroupBy[
rules,
(#[[1, 1]] &) ->
(If[Length[#[[1]]] === 1, #[[2]], #[[1, 2 ;;]] -> #[[2]]] &),
groupMe
],
rules[[1]]
]
groupMe[B]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's an inefficient but reasonably simple way:
groupMe[rules_] :=
If[Head[rules[[1]]] === Rule,
Values@GroupBy[
rules,
(#[[1, 1]] &) ->
(If[Length[#[[1]]] === 1, #[[2]], #[[1, 2 ;;]] -> #[[2]]] &),
groupMe
],
rules[[1]]
]
groupMe[B]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's an inefficient but reasonably simple way:
groupMe[rules_] :=
If[Head[rules[[1]]] === Rule,
Values@GroupBy[
rules,
(#[[1, 1]] &) ->
(If[Length[#[[1]]] === 1, #[[2]], #[[1, 2 ;;]] -> #[[2]]] &),
groupMe
],
rules[[1]]
]
groupMe[B]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
Here's an inefficient but reasonably simple way:
groupMe[rules_] :=
If[Head[rules[[1]]] === Rule,
Values@GroupBy[
rules,
(#[[1, 1]] &) ->
(If[Length[#[[1]]] === 1, #[[2]], #[[1, 2 ;;]] -> #[[2]]] &),
groupMe
],
rules[[1]]
]
groupMe[B]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
answered 2 hours ago
b3m2a1b3m2a1
28.3k358163
28.3k358163
add a comment |
add a comment |
$begingroup$
Here's a convoluted way using pattern replacements:
DeleteCases[
With[m = Max[Length /@ Keys[B]],
Array[
List,
Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]
] /.
Map[
Fold[
Insert[
#, ___,
_,
Append[ConstantArray[1, #2], -1]] &,
#[[1]],
Range[m - Length[#[[1]]]]
] -> #[[2]] &,
B
]
],
__Integer,
Infinity
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's a convoluted way using pattern replacements:
DeleteCases[
With[m = Max[Length /@ Keys[B]],
Array[
List,
Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]
] /.
Map[
Fold[
Insert[
#, ___,
_,
Append[ConstantArray[1, #2], -1]] &,
#[[1]],
Range[m - Length[#[[1]]]]
] -> #[[2]] &,
B
]
],
__Integer,
Infinity
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
add a comment |
$begingroup$
Here's a convoluted way using pattern replacements:
DeleteCases[
With[m = Max[Length /@ Keys[B]],
Array[
List,
Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]
] /.
Map[
Fold[
Insert[
#, ___,
_,
Append[ConstantArray[1, #2], -1]] &,
#[[1]],
Range[m - Length[#[[1]]]]
] -> #[[2]] &,
B
]
],
__Integer,
Infinity
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
$endgroup$
Here's a convoluted way using pattern replacements:
DeleteCases[
With[m = Max[Length /@ Keys[B]],
Array[
List,
Max /@ Transpose[PadRight[#, m] & /@ Keys[B]]
] /.
Map[
Fold[
Insert[
#, ___,
_,
Append[ConstantArray[1, #2], -1]] &,
#[[1]],
Range[m - Length[#[[1]]]]
] -> #[[2]] &,
B
]
],
__Integer,
Infinity
]
a, b, c, d, e, f, g, h, i, j, k, l, m, n
answered 2 hours ago
b3m2a1b3m2a1
28.3k358163
28.3k358163
add a comment |
add a comment |
Thanks for contributing an answer to Mathematica Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e)
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom))
StackExchange.using('gps', function() StackExchange.gps.track('embedded_signup_form.view', location: 'question_page' ); );
$window.unbind('scroll', onScroll);
;
$window.on('scroll', onScroll);
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f194217%2fhow-to-invert-mapindexed-on-a-ragged-structure-how-to-construct-a-tree-from-rul%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e)
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom))
StackExchange.using('gps', function() StackExchange.gps.track('embedded_signup_form.view', location: 'question_page' ); );
$window.unbind('scroll', onScroll);
;
$window.on('scroll', onScroll);
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e)
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom))
StackExchange.using('gps', function() StackExchange.gps.track('embedded_signup_form.view', location: 'question_page' ); );
$window.unbind('scroll', onScroll);
;
$window.on('scroll', onScroll);
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e)
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom))
StackExchange.using('gps', function() StackExchange.gps.track('embedded_signup_form.view', location: 'question_page' ); );
$window.unbind('scroll', onScroll);
;
$window.on('scroll', onScroll);
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown