How to leave only the following strings? Planned maintenance scheduled April 23, 2019 at 23:30...

What could prevent concentrated local exploration?

Can 'non' with gerundive mean both lack of obligation and negative obligation?

What is the definining line between a helicopter and a drone a person can ride in?

Can this water damage be explained by lack of gutters and grading issues?

/bin/ls sorts differently than just ls

How to ask rejected full-time candidates to apply to teach individual courses?

A German immigrant ancestor has a "Registration Affidavit of Alien Enemy" on file. What does that mean exactly?

Reflections in a Square

Should man-made satellites feature an intelligent inverted "cow catcher"?

Why not use the yoke to control yaw, as well as pitch and roll?

Pointing to problems without suggesting solutions

Meaning of "Not holding on that level of emuna/bitachon"

How to get a single big right brace?

Has a Nobel Peace laureate ever been accused of war crimes?

When does Bran Stark remember Jamie pushing him?

How to charge percentage of transaction cost?

Is "ein Herz wie das meine" an antiquated or colloquial use of the possesive pronoun?

How to mute a string and play another at the same time

What kind of capacitor is this in the image?

Putting Ant-Man on house arrest

Short story about an alien named Ushtu(?) coming from a future Earth, when ours was destroyed by a nuclear explosion

Why these surprising proportionalities of integrals involving odd zeta values?

Does the Pact of the Blade warlock feature allow me to customize the properties of the pact weapon I create?

Unix AIX passing variable and arguments to expect and spawn



How to leave only the following strings?



Planned maintenance scheduled April 23, 2019 at 23:30 UTC (7:30pm US/Eastern)
Announcing the arrival of Valued Associate #679: Cesar Manara
Unicorn Meta Zoo #1: Why another podcast?How can I create a class of matrices programmatically?Manipulate excel file and plotHow do I partition a matrix?How to create a table of tables?Turn the following values into percentageHow to select the data in a given way?Reading CSV data from a streamHow to remove from the data the rows of with fixed number of elements?Padding lists for accurate plottingHow to remove the given columns and strings?












2












$begingroup$


Consider a data having the form



data = {{1,7,4,6},{1,6,4,8},{2,4,9,2},{E,...},{1,4,6,3},{4,4,6,2},{E,...},...}


i.e., some number $n_{1}$ of rows followed by row ${E,...}$, then some number $n_{2}$ of rows followed by row ${E,...}$ and so on.



Could you please tell me how to leave only the last rows before ${E,}$, i.e. to obtain



subdata= {{2,4,9,2},{4,4,6,2},...}?





list-manipulation data







share|improve this question









$endgroup$








  • 1




    $begingroup$
    e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
    $endgroup$
    – C. E.
    3 hours ago
















2












$begingroup$


Consider a data having the form



data = {{1,7,4,6},{1,6,4,8},{2,4,9,2},{E,...},{1,4,6,3},{4,4,6,2},{E,...},...}


i.e., some number $n_{1}$ of rows followed by row ${E,...}$, then some number $n_{2}$ of rows followed by row ${E,...}$ and so on.



Could you please tell me how to leave only the last rows before ${E,}$, i.e. to obtain



subdata= {{2,4,9,2},{4,4,6,2},...}?





list-manipulation data







share|improve this question









$endgroup$








  • 1




    $begingroup$
    e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
    $endgroup$
    – C. E.
    3 hours ago














2












2








2





$begingroup$


Consider a data having the form



data = {{1,7,4,6},{1,6,4,8},{2,4,9,2},{E,...},{1,4,6,3},{4,4,6,2},{E,...},...}


i.e., some number $n_{1}$ of rows followed by row ${E,...}$, then some number $n_{2}$ of rows followed by row ${E,...}$ and so on.



Could you please tell me how to leave only the last rows before ${E,}$, i.e. to obtain



subdata= {{2,4,9,2},{4,4,6,2},...}?





list-manipulation data







share|improve this question









$endgroup$




Consider a data having the form



data = {{1,7,4,6},{1,6,4,8},{2,4,9,2},{E,...},{1,4,6,3},{4,4,6,2},{E,...},...}


i.e., some number $n_{1}$ of rows followed by row ${E,...}$, then some number $n_{2}$ of rows followed by row ${E,...}$ and so on.



Could you please tell me how to leave only the last rows before ${E,}$, i.e. to obtain



subdata= {{2,4,9,2},{4,4,6,2},...}?





list-manipulation data




list-manipulation data






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 3 hours ago









John TaylorJohn Taylor

787211




787211








  • 1




    $begingroup$
    e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
    $endgroup$
    – C. E.
    3 hours ago














  • 1




    $begingroup$
    e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
    $endgroup$
    – C. E.
    3 hours ago








1




1




$begingroup$
e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
$endgroup$
– C. E.
3 hours ago




$begingroup$
e.g. SequenceCases[data, {x_List, {E, ___}} :> x]
$endgroup$
– C. E.
3 hours ago










2 Answers
2






active

oldest

votes


















2












$begingroup$

Try SequenceCases:



data = {{1, 7, 4, 6}, {1, 6, 4, 8}, {2, 4, 9, 2}, {E, 1, 2, 3}, 

        {1, 4, 6, 3}, {4, 4, 6, 2}, {E, 4, 5, 6}}

SequenceCases[data, {p_, {E, ___}} :> p]


yields



{{2, 4, 9, 2}, {4, 4, 6, 2}}





share|improve this answer









$endgroup$





















    2












    $begingroup$

    The most idiomatic solution to this problem is, in my opinion, pattern matching (as Sakra has also answered):



    SequenceCases[data, {x_List, {E, ___}} :> x]



    {{2, 4, 9, 2}, {4, 4, 6, 2}}




    But the problem also lends itself to functional solutions, e.g.:



    pairs = Partition[data, 2, 1];
    
If[#[[2, 1]] == E, #[[1]], Nothing] & /@ pairs



    {{2, 4, 9, 2}, {4, 4, 6, 2}}




    Or in one go:



    BlockMap[If[#[[2, 1]] == E, #[[1]], Nothing] &, data, 2, 1]



    {{2, 4, 9, 2}, {4, 4, 6, 2}}







    share|improve this answer











    $endgroup$














      Your Answer








      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


















      StackExchange.ready(
      function () {
      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f195786%2fhow-to-leave-only-the-following-strings%23new-answer', 'question_page');
      }
      );

      Post as a guest















      Required, but never shown

























      2 Answers
      2






      active

      oldest

      votes








      2 Answers
      2






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      2












      $begingroup$

      Try SequenceCases:



      data = {{1, 7, 4, 6}, {1, 6, 4, 8}, {2, 4, 9, 2}, {E, 1, 2, 3}, 
      
        {1, 4, 6, 3}, {4, 4, 6, 2}, {E, 4, 5, 6}}
      
SequenceCases[data, {p_, {E, ___}} :> p]


      yields



      {{2, 4, 9, 2}, {4, 4, 6, 2}}





      share|improve this answer









      $endgroup$


















        2












        $begingroup$

        Try SequenceCases:



        data = {{1, 7, 4, 6}, {1, 6, 4, 8}, {2, 4, 9, 2}, {E, 1, 2, 3}, 
        
        {1, 4, 6, 3}, {4, 4, 6, 2}, {E, 4, 5, 6}}
        
SequenceCases[data, {p_, {E, ___}} :> p]


        yields



        {{2, 4, 9, 2}, {4, 4, 6, 2}}





        share|improve this answer









        $endgroup$
















          2












          2








          2





          $begingroup$

          Try SequenceCases:



          data = {{1, 7, 4, 6}, {1, 6, 4, 8}, {2, 4, 9, 2}, {E, 1, 2, 3}, 
          
        {1, 4, 6, 3}, {4, 4, 6, 2}, {E, 4, 5, 6}}
          
SequenceCases[data, {p_, {E, ___}} :> p]


          yields



          {{2, 4, 9, 2}, {4, 4, 6, 2}}





          share|improve this answer









          $endgroup$



          Try SequenceCases:



          data = {{1, 7, 4, 6}, {1, 6, 4, 8}, {2, 4, 9, 2}, {E, 1, 2, 3}, 
          
        {1, 4, 6, 3}, {4, 4, 6, 2}, {E, 4, 5, 6}}
          
SequenceCases[data, {p_, {E, ___}} :> p]


          yields



          {{2, 4, 9, 2}, {4, 4, 6, 2}}






          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 3 hours ago









          sakrasakra

          2,8231429




          2,8231429























              2












              $begingroup$

              The most idiomatic solution to this problem is, in my opinion, pattern matching (as Sakra has also answered):



              SequenceCases[data, {x_List, {E, ___}} :> x]



              {{2, 4, 9, 2}, {4, 4, 6, 2}}




              But the problem also lends itself to functional solutions, e.g.:



              pairs = Partition[data, 2, 1];
              
If[#[[2, 1]] == E, #[[1]], Nothing] & /@ pairs



              {{2, 4, 9, 2}, {4, 4, 6, 2}}




              Or in one go:



              BlockMap[If[#[[2, 1]] == E, #[[1]], Nothing] &, data, 2, 1]



              {{2, 4, 9, 2}, {4, 4, 6, 2}}







              share|improve this answer











              $endgroup$


















                2












                $begingroup$

                The most idiomatic solution to this problem is, in my opinion, pattern matching (as Sakra has also answered):



                SequenceCases[data, {x_List, {E, ___}} :> x]



                {{2, 4, 9, 2}, {4, 4, 6, 2}}




                But the problem also lends itself to functional solutions, e.g.:



                pairs = Partition[data, 2, 1];
                
If[#[[2, 1]] == E, #[[1]], Nothing] & /@ pairs



                {{2, 4, 9, 2}, {4, 4, 6, 2}}




                Or in one go:



                BlockMap[If[#[[2, 1]] == E, #[[1]], Nothing] &, data, 2, 1]



                {{2, 4, 9, 2}, {4, 4, 6, 2}}







                share|improve this answer











                $endgroup$
















                  2












                  2








                  2





                  $begingroup$

                  The most idiomatic solution to this problem is, in my opinion, pattern matching (as Sakra has also answered):



                  SequenceCases[data, {x_List, {E, ___}} :> x]



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}




                  But the problem also lends itself to functional solutions, e.g.:



                  pairs = Partition[data, 2, 1];
                  
If[#[[2, 1]] == E, #[[1]], Nothing] & /@ pairs



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}




                  Or in one go:



                  BlockMap[If[#[[2, 1]] == E, #[[1]], Nothing] &, data, 2, 1]



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}







                  share|improve this answer











                  $endgroup$



                  The most idiomatic solution to this problem is, in my opinion, pattern matching (as Sakra has also answered):



                  SequenceCases[data, {x_List, {E, ___}} :> x]



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}




                  But the problem also lends itself to functional solutions, e.g.:



                  pairs = Partition[data, 2, 1];
                  
If[#[[2, 1]] == E, #[[1]], Nothing] & /@ pairs



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}




                  Or in one go:



                  BlockMap[If[#[[2, 1]] == E, #[[1]], Nothing] &, data, 2, 1]



                  {{2, 4, 9, 2}, {4, 4, 6, 2}}








                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited 1 hour ago

























                  answered 3 hours ago









                  C. E.C. E.

                  51.4k3101207




                  51.4k3101207






























                      draft saved

                      draft discarded




















































                      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.




                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function () {
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathematica.stackexchange.com%2fquestions%2f195786%2fhow-to-leave-only-the-following-strings%23new-answer', 'question_page');
                      }
                      );

                      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







                      -

                      Popular posts from this blog

                      Gersau Kjelder | Navigasjonsmeny46°59′0″N 8°31′0″E46°59′0″N...

                      Image
                      Tidlegare republikkarSkipingar i 1433Kommunar i SchwyzDistrikt i SchwyzNedleggingar i 1798Stader ved Vierwaldstättersee kommunekantonenSchwyzSveitskm²VierwaldstätterseeLauerz Gersau Kommunevåpenet til Gersau Plassering Styresmakter Land   Sveits Kanton kantonen Schwyz Distrikt Gersau Språk tysk Geografi Flatevidd  - kommune 23,70 km² Innbyggjarar  - kommune (desember 2010)    - folketettleik 2 094   88,4 /km² Koordinatar 46°59′0″N 8°31′0″E  Koordinatar: 46°59′0″N 8°31′0″E  Høgd over havet 435 moh Diverse annan informasjon Postnummer 6442 Nettstad: www.gersau.ch Freistaat und Republik Gersau Fristaten og republikken Gersau By-republikk og alliert protektorat i Det gamle sveitsiske eidsforundet ←   ← 1433–1798 1814–1818 →   → Hovudstad Gersau Styreform Republikk Historisk periode Tidleg moderne tid  - Kjøpte fridom frå
                      Read more

                      What is the “three and three hundred thousand syndrome”?Who wrote the book Arena?What five creatures were...

                      Image
                      What happens when the centripetal force is equal and opposite to the centrifugal force? Why is "la Gestapo" feminine? Nested Dynamic SOQL Query How are passwords stolen from companies if they only store hashes? Exposing a company lying about themselves in a tightly knit industry: Is my career at risk on the long run? Can "few" be used as a subject? If so, what is the rule? Why are there no stars visible in cislunar space? categorizing a variable turns it from insignificant to significant Do I need an EFI partition for each 18.04 ubuntu I have on my HD? What are the consequences of changing the number of hours in
                      Read more

                      Are all UTXOs locked by an address spent in a transaction?UTXO all sent to change address?Signing...

                      Image
                      How can I be pwned if I'm not registered on the compromised site? Caulking a corner instead of taping with joint compound? What is a term for a function that when called repeatedly, has the same effect as calling once? How does insurance birth control work? School performs periodic password audits. Is my password compromised? Practical reasons to have both a large police force and bounty hunting network? Why would the IRS ask for birth certificates or even audit a small tax return? Is every open circuit a capacitor? Make me a metasequence How can I highlight parts in a screenshot Is there
                      Read more