Ttyjukl

Input two commands to a new terminal?

Weird behaviour when using querySelector

Mapping arrows in commutative diagrams

Is every set a filtered colimit of finite sets?

What is the offset in a seaplane's hull?

Can I find out the caloric content of bread by dehydrating it?

What do the Banks children have against barley water?

Latin words with no plurals in English

Was there ever an axiom rendered a theorem?

New order #4: World

Why did the Germans forbid the possession of pet pigeons in Rostov-on-Don in 1941?

Why doesn't a const reference extend the life of a temporary object passed via a function?

Is there a way to make member function NOT callable from constructor?

Email Account under attack (really) - anything I can do?

Is "plugging out" electronic devices an American expression?

How to manage monthly salary

What is GPS' 19 year rollover and does it present a cybersecurity issue?

What does 'script /dev/null' do?

Are cabin dividers used to "hide" the flex of the airplane?

Is Social Media Science Fiction?

Ideas for colorfully and clearly highlighting graph edges according to weights

What are the advantages and disadvantages of running one shots compared to campaigns?

Eliminate empty elements from a list with a specific pattern

Why is my log file so massive? 22gb. I am running log backups

Eliminate empty elements from a list with a specific pattern

List operation on specific elementsSelect elements from list with given headSelecting elements from a list with nullsReplace empty list elements with patternReplacing Non-Constant Elements from List with Patternselecting elements from a list with two numbersRemoving elements of a specific length from a listEliminate types of elements from the listListPlot3D with empty matrix elementsDelete a large pattern from one list

2

1

$begingroup$

I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:

list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}

and I need to obtain

list={"a12-b11-{1}", "d33-c22-{2}"}

The list was created using

list =  Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> 

        ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]  ]], 

        {i, 1, 4}, {j, 1, 4}], 1]

and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as

list//."a11-b11-{}"-> Sequence[]

but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.

list-manipulation filtering

share|improve this question

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Have a look at DeleteCases and StringMatchQ or StringContainsQ.
  $endgroup$
  – b.gatessucks
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  I think it would be more efficient to first filter out the unwanted cases in the int function, and then construct strings only from the remaining ones.
  $endgroup$
  – Roman
  5 hours ago
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  @b.gatessucks Thank you, I will look those option in Mathematica.
  $endgroup$
  – mors
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  @Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
  $endgroup$
  – mors
  5 hours ago
  

  
  
  
  

add a comment | 

2

1

$begingroup$

I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:

list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}

and I need to obtain

list={"a12-b11-{1}", "d33-c22-{2}"}

The list was created using

list =  Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> 

        ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]  ]], 

        {i, 1, 4}, {j, 1, 4}], 1]

and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as

list//."a11-b11-{}"-> Sequence[]

but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.

list-manipulation filtering

share|improve this question

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Have a look at DeleteCases and StringMatchQ or StringContainsQ.
  $endgroup$
  – b.gatessucks
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  I think it would be more efficient to first filter out the unwanted cases in the int function, and then construct strings only from the remaining ones.
  $endgroup$
  – Roman
  5 hours ago
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  @b.gatessucks Thank you, I will look those option in Mathematica.
  $endgroup$
  – mors
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  @Roman You are right, but I am new ih this cases stuf in Mathematica and I did no know how to do it when I created the list.
  $endgroup$
  – mors
  5 hours ago
  

  
  
  
  

add a comment | 

$begingroup$

I am really new in this patterns part of Mathematica. Basically what I need to do is eliminate null elements from a list but that has a specific name before the empty element. For example, my list is:

list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}

and I need to obtain

list={"a12-b11-{1}", "d33-c22-{2}"}

The list was created using

list =  Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> 

        ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]  ]], 

        {i, 1, 4}, {j, 1, 4}], 1]

and for some values it writtes {} because there is not a value equal to $0.5$. Until now I have been able to do it term by term as

list//."a11-b11-{}"-> Sequence[]

but the real list contains a lot of elements and could be almost impossible to do it that way to solve the problem. I think my main problem is that I am not sure how to specify the pattern search (something like " *-name " in gnu/linux). Is there a wise way to do this?. Thanks in advance.

list-manipulation filtering

share|improve this question

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

$endgroup$

list={"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"}

list={"a12-b11-{1}", "d33-c22-{2}"}

list =  Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> 

        ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]  ]], 

        {i, 1, 4}, {j, 1, 4}], 1]

list//."a11-b11-{}"-> Sequence[]

share|improve this question

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

share|improve this question

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

edited 29 mins ago

Roman

4,62511128

edited 29 mins ago

Roman

4,62511128

asked 5 hours ago

morsmors

446

asked 5 hours ago

morsmors

446

1 Answer
1

active

oldest

votes

5

$begingroup$

If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:

list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};

Select[list, Not@*StringMatchQ[__ ~~ "{}"]]

{"a12-b11-{1}", "d33-c22-{2}"}

You could also Select before making the strings:

L = DeleteCases[

      Flatten[

        Table[

          {namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},

          {i, 4}, {j, 4}],

        1],

      {_, _, {}}];

and then make these into strings:

StringRiffle[ToString /@ #, "-"] & /@ L

I can't check this because you didn't supply functioning code.

share|improve this answer

edited 1 hour ago

answered 5 hours ago

RomanRoman

4,62511128

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
  $endgroup$
  – mors
  5 hours ago
  
  
  

  
  
  
  

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
});


}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f194815%2feliminate-empty-elements-from-a-list-with-a-specific-pattern%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

5

$begingroup$

If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:

list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};

Select[list, Not@*StringMatchQ[__ ~~ "{}"]]

{"a12-b11-{1}", "d33-c22-{2}"}

You could also Select before making the strings:

L = DeleteCases[

      Flatten[

        Table[

          {namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},

          {i, 4}, {j, 4}],

        1],

      {_, _, {}}];

and then make these into strings:

StringRiffle[ToString /@ #, "-"] & /@ L

I can't check this because you didn't supply functioning code.

share|improve this answer

edited 1 hour ago

answered 5 hours ago

RomanRoman

4,62511128

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
  $endgroup$
  – mors
  5 hours ago
  
  
  

  
  
  
  

add a comment | 

5

$begingroup$

If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:

list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};

Select[list, Not@*StringMatchQ[__ ~~ "{}"]]

{"a12-b11-{1}", "d33-c22-{2}"}

You could also Select before making the strings:

L = DeleteCases[

      Flatten[

        Table[

          {namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},

          {i, 4}, {j, 4}],

        1],

      {_, _, {}}];

and then make these into strings:

StringRiffle[ToString /@ #, "-"] & /@ L

I can't check this because you didn't supply functioning code.

share|improve this answer

edited 1 hour ago

answered 5 hours ago

RomanRoman

4,62511128

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Thank you, I forgot to specify the way the list is created. I create the list as 'list = Flatten[Table[ ToString[namea[[i]] <> "-" <> nameb[[j]] <> "-" <> ToString[ Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1] ]], {i, 1, 4}, {j, 1, 4}], 1] '
  $endgroup$
  – mors
  5 hours ago
  
  
  

  
  
  
  

add a comment | 

$begingroup$

If the list elements are strings, as it appears after your comment, you can use Select with a string pattern:

list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};

Select[list, Not@*StringMatchQ[__ ~~ "{}"]]

{"a12-b11-{1}", "d33-c22-{2}"}

You could also Select before making the strings:

L = DeleteCases[

      Flatten[

        Table[

          {namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},

          {i, 4}, {j, 4}],

        1],

      {_, _, {}}];

and then make these into strings:

StringRiffle[ToString /@ #, "-"] & /@ L

I can't check this because you didn't supply functioning code.

share|improve this answer

edited 1 hour ago

answered 5 hours ago

RomanRoman

4,62511128

$endgroup$

list = {"a11-b11-{}", "a12-b11-{1}", "c11-d22-{}", "d33-c22-{2}"};

Select[list, Not@*StringMatchQ[__ ~~ "{}"]]

L = DeleteCases[

      Flatten[

        Table[

          {namea[[i]], nameb[[j]], Select[int[i, j, 0.5], Abs[#] == 0.5 &, 1]},

          {i, 4}, {j, 4}],

        1],

      {_, _, {}}];

StringRiffle[ToString /@ #, "-"] & /@ L

share|improve this answer

edited 1 hour ago

answered 5 hours ago

RomanRoman

4,62511128

answered 5 hours ago

RomanRoman

4,62511128

answered 5 hours ago

RomanRoman

4,62511128