water.rapids.ASTApply Maven / Gradle / Ivy

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package water.rapids;

import water.*;
import water.fvec.*;

import java.util.ArrayList;

/**
* R's `apply`
*/
public class ASTApply extends ASTOp {
  protected static int _margin;  // 1 => work on rows; 2 => work on columns
  protected static String _fun;  // the function to run on the frame
  protected static AST[] _fun_args; // any additional args to _fun
  static final String VARS[] = new String[]{ "", "ary", "MARGIN", "FUN", "..."};
  public ASTApply( ) { super(VARS); }
  @Override String opStr(){ return "apply";}
  @Override ASTOp make() {return new ASTApply();}
  @Override ASTApply parse_impl(Exec E) {
    AST ary = E.parse();    // parse the array
    AST a = E.parse();      // parse the margin, must be 1 or 2
    if( a instanceof ASTNum ) _margin=(int)((ASTNum)a)._d;
    else throw new IllegalArgumentException("`MARGIN` must be either 1 or 2, it cannot be both.");
    _fun = ((ASTId)E.parse())._id;  // parse the function

    // parse any additional arguments
    ArrayList fun_args = new ArrayList<>();
    while( !E.isEnd() )fun_args.add(E.parse());
    E.eatEnd();

    ASTApply res = (ASTApply)clone();
    res._asts = new AST[]{ary};
    if (fun_args.size() > 0) _fun_args = fun_args.toArray(new AST[fun_args.size()]);
    else                     _fun_args = null;
    return res;
  }
  @Override void apply(Env env) {
    String err="Result of function produced more than a single column!";
    final ASTOp FUN = ASTOp.get(_fun);   // function never goes on the stack... distinctly not 1st class...

    // PEEK everything from the stack (do not POP)
    Frame fr2 = null;  // results Frame
    Frame fr = env.popAry();

    // apply FUN to each column;
    // assume work is independent of Vec order => otherwise asking for trouble anyways.
    // Types of results:
    //   A single row: Each col produces a single number result.
    //   A new array: Each column produces a new column
    //   If a new array, columns must be align'able.
    if( _margin == 2) {
      double[] row_result;
      Vec[] vecs_result;

      boolean isRow = false;
      Futures fs = new Futures();
      Key key;
      AppendableVec v=null;
      NewChunk chunk=null;
      Vec[] vecs = new Vec[fr.numCols()];
      for(int i=0;i fun_args = new ArrayList<>();
    while(E.skipWS().hasNext()) {
      fun_args.add(E.parse());
    }
    ASTSApply res = (ASTSApply)clone();
    res._asts = new AST[]{ary};
    if (fun_args.size() > 0) _fun_args = fun_args.toArray(new AST[fun_args.size()]);
    return res;
  }
  @Override void apply(Env env) {
    super.apply(env);
  }
}

// --------------------------------------------------------------------------
// unique(ary)
// Returns only the unique rows

//class ASTUnique extends ASTddply {
//  static final String VARS[] = new String[]{ "", "ary"};
//  ASTUnique( ) { super(VARS, new Type[]{Type.ARY, Type.ARY}); }
//  @Override String opStr(){ return "unique";}
//  @Override ASTOp make() {return new ASTUnique();}
//  @Override void apply(Env env, int argcnt, ASTApply apply) {
//    Thread cThr = Thread.currentThread();
//    Frame fr = env.peekAry();
//    int cols[] = new int[fr.numCols()];
//    for( int i=0; i