Create Permutations from Dictionary<string, List<string>>

Collapse
This topic is closed.
X
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Assimalyst
    #1

    Create Permutations from Dictionary<string, List<string>>

    Hi

    I have a Dictionary<stri ng, List<string>>, which i have successfully
    filled. My problem is I need to create a filter expression using all
    possible permutations of its contents.

    i.e. the dictionary essentially creates the following array:

    Key Value

    Column1 1
    Column1 2
    Column2 17

    I want to then create an number of filter expressions:

    Column1 = 1 AND Column2 = 17
    Column1 = 2 AND Column2 = 17

    I used a permutation library i found PermuteUtils (
    http://www.koders.com/csharp/fid3768925A9A54C7E9E853737EE8E638B71457A936.aspx

    ) and the following code:

    Dictionary<stri ng, List<string>dis tinctCellValues = new
    Dictionary<stri ng, List<string>>() ;
    ArrayList queryClause = new ArrayList();

    {
    foreach (KeyValuePair<s tring, List<string>kvp in
    distinctCellVal ues)
    {
    foreach (string value in kvp.Value)
    {
    queryClause.Add (kvp.Key + " = " + value);
    }
    }

    //Convert array to string array
    string[] queryClauseStri ng = queryClause.ToA rray(typeof(str ing)) as
    string[];

    CreateFilterPer mutations<strin g>(queryClauseS tring,
    distinctCellVal ues.Count);
    }

    private void CreateFilterPer mutations<T>(IE numerable<Tinpu t, int
    count)
    {
    foreach (IEnumerable<Tp ermutation in
    PermuteUtils.Pe rmute<T>(input, count))
    {
    foreach (T i in permutation)
    {
    filterExpressio ns.Add(i);
    }
    }
    }

    This seems to work OK as far as running the CreateFilterPer mutations
    method, where i just cannot get it to do what i need.

    I've manage to get myself very confused by all this, and this only
    contains 2 columns. Potentially i could need to be generating
    permutations of 10 columns/values or more!! I'm hoping someone can
    straighten out my thoughts before my head explodes!!

    Thanks
    Tags: None
    • Fred Mellender
      #2
      Re: Create Permutations from Dictionary&lt;s tring, List&lt;string& gt;&gt;

      There is a good chance I don't understand your problem, but here is my take:

      I don't think you want the permutations of the array elements, but instead
      want a subset of the Cartesian product of the array with itself. E.G. if
      the array is A= [a, b, c], the Cartesian product A x A is
      {(a,a), (a,b), (a,c), (b,a), (b,b), (b,c), (c,a), (c,b), (c,c)}. The subset
      you want excludes an element whose coords are the same, and considers as
      duplicates 2 elements that have the same coords (e.g. (a,b) and (b,a) are
      the same).

      So, you want {(a,b), (a,c), (b,co)}

      If you only have a single array, X, crossed only once with itself,
      containing more than one element, some potential pseudo code would be:

      for (int i = 0; i < x.Length-1; i++)
      {
      for (int j = i+1; j < x.Length; j++)
      {
      myFilterList.Ad d(x[i].MyToString() + " AND " +
      x[j].MyToString())
      }
      }

      In your case, x is the list of KeyValue pairs from the dictionary, and you
      need to convert each KeyValue to a string via MyToString(), so as to form a
      filter, which you add to a list, myFilterList.

      What I don't understand about your example:
      You have the same key, Column1 associated with two different values. I
      don't think the Dictionary allows this.


      "Assimalyst " <c_oxtoby@hotma il.comwrote in message
      news:8c0f0921-c3a0-432f-a953-68e1a533d6e7@s8 g2000prg.google groups.com...
      Hi
      >
      I have a Dictionary<stri ng, List<string>>, which i have successfully
      filled. My problem is I need to create a filter expression using all
      possible permutations of its contents.
      >
      i.e. the dictionary essentially creates the following array:
      >
      Key Value
      >
      Column1 1
      Column1 2
      Column2 17
      >
      I want to then create an number of filter expressions:
      >
      Column1 = 1 AND Column2 = 17
      Column1 = 2 AND Column2 = 17
      >
      I used a permutation library i found PermuteUtils (
      http://www.koders.com/csharp/fid3768925A9A54C7E9E853737EE8E638B71457A936.aspx

      ) and the following code:
      >
      Dictionary<stri ng, List<string>dis tinctCellValues = new
      Dictionary<stri ng, List<string>>() ;
      ArrayList queryClause = new ArrayList();
      >
      {
      foreach (KeyValuePair<s tring, List<string>kvp in
      distinctCellVal ues)
      {
      foreach (string value in kvp.Value)
      {
      queryClause.Add (kvp.Key + " = " + value);
      }
      }
      >
      //Convert array to string array
      string[] queryClauseStri ng = queryClause.ToA rray(typeof(str ing)) as
      string[];
      >
      CreateFilterPer mutations<strin g>(queryClauseS tring,
      distinctCellVal ues.Count);
      }
      >
      private void CreateFilterPer mutations<T>(IE numerable<Tinpu t, int
      count)
      {
      foreach (IEnumerable<Tp ermutation in
      PermuteUtils.Pe rmute<T>(input, count))
      {
      foreach (T i in permutation)
      {
      filterExpressio ns.Add(i);
      }
      }
      }
      >
      This seems to work OK as far as running the CreateFilterPer mutations
      method, where i just cannot get it to do what i need.
      >
      I've manage to get myself very confused by all this, and this only
      contains 2 columns. Potentially i could need to be generating
      permutations of 10 columns/values or more!! I'm hoping someone can
      straighten out my thoughts before my head explodes!!
      >
      Thanks

        Comment

        • Assimalyst
          #3
          Re: Create Permutations from Dictionary&lt;s tring, List&lt;string& gt;&gt;

          Thank you Fred.

          I think i had confused myself. Not sure I want permutations but rather
          combinations.

          Your code sample has given me some ideas that i think i can get
          working with a bit of expansion.
          I'll keep playing with it . . .

          By the way, i think you understood my problem exactly. The bit you
          didn't understand was just the way i represented it. I didn't have
          duplicate keys it was more like

          Column1 { 1, 2 }
          Column2 { 17 }

          Thanks again


          On Nov 30, 6:14 pm, "Fred Mellender" <nospamPlease_f red...@gmail.co m>
          wrote:
          There is a good chance I don't understand your problem, but here is my take:
          >
          I don't think you want the permutations of the array elements, but instead
          want a subset of the Cartesian product of the array with itself. E.G. if
          the array is A= [a, b, c], the Cartesian product A x A is
          {(a,a), (a,b), (a,c), (b,a), (b,b), (b,c), (c,a), (c,b), (c,c)}. The subset
          you want excludes an element whose coords are the same, and considers as
          duplicates 2 elements that have the same coords (e.g. (a,b) and (b,a) are
          the same).
          >
          So, you want {(a,b), (a,c), (b,co)}
          >
          If you only have a single array, X, crossed only once with itself,
          containing more than one element, some potential pseudo code would be:
          >
          for (int i = 0; i < x.Length-1; i++)
          {
          for (int j = i+1; j < x.Length; j++)
          {
          myFilterList.Ad d(x[i].MyToString() + " AND " +
          x[j].MyToString())
          }
          >
          }
          >
          In your case, x is the list of KeyValue pairs from the dictionary, and you
          need to convert each KeyValue to a string via MyToString(), so as to form a
          filter, which you add to a list, myFilterList.
          >
          What I don't understand about your example:
          You have the same key, Column1 associated with two different values. I
          don't think the Dictionary allows this.
          >
          "Assimalyst " <c_oxt...@hotma il.comwrote in message
          >
          news:8c0f0921-c3a0-432f-a953-68e1a533d6e7@s8 g2000prg.google groups.com...
          >
          Hi
          >
          I have a Dictionary<stri ng, List<string>>, which i have successfully
          filled. My problem is I need to create a filter expression using all
          possible permutations of its contents.
          >
          i.e. the dictionary essentially creates the following array:
          >
          Key Value
          >
          Column1 1
          Column1 2
          Column2 17
          >
          I want to then create an number of filter expressions:
          >
          Column1 = 1 AND Column2 = 17
          Column1 = 2 AND Column2 = 17
          >
          I used a permutation library i found PermuteUtils (
          http://www.koders.com/csharp/fid3768...EE8E638B71457A...
          ) and the following code:
          >
          Dictionary<stri ng, List<string>dis tinctCellValues = new
          Dictionary<stri ng, List<string>>() ;
          ArrayList queryClause = new ArrayList();
          >
          {
          foreach (KeyValuePair<s tring, List<string>kvp in
          distinctCellVal ues)
          {
          foreach (string value in kvp.Value)
          {
          queryClause.Add (kvp.Key + " = " + value);
          }
          }
          >
          //Convert array to string array
          string[] queryClauseStri ng = queryClause.ToA rray(typeof(str ing)) as
          string[];
          >
          CreateFilterPer mutations<strin g>(queryClauseS tring,
          distinctCellVal ues.Count);
          }
          >
          private void CreateFilterPer mutations<T>(IE numerable<Tinpu t, int
          count)
          {
          foreach (IEnumerable<Tp ermutation in
          PermuteUtils.Pe rmute<T>(input, count))
          {
          foreach (T i in permutation)
          {
          filterExpressio ns.Add(i);
          }
          }
          }
          >
          This seems to work OK as far as running the CreateFilterPer mutations
          method, where i just cannot get it to do what i need.
          >
          I've manage to get myself very confused by all this, and this only
          contains 2 columns. Potentially i could need to be generating
          permutations of 10 columns/values or more!! I'm hoping someone can
          straighten out my thoughts before my head explodes!!
          >
          Thanks

            Comment

            Previous template Next
            Working...