Package opendap.dap

Class DArray

  • All Implemented Interfaces:
    Serializable, Cloneable, ClientIO
    public class DArray
extends DVector
    This class is used to hold arrays of other OPeNDAP data. The elements of the array can be simple or compound data types. There is no limit on the number of dimensions an array can have, or on the size of each dimension.

    If desired, the user can give each dimension of an array a name. You can, for example, have a 360x180 array of temperatures, covering the whole globe with one-degree squares. In this case, you could name the first dimension "Longitude" and the second dimension "Latitude". This can help prevent a great deal of confusion.

    The DArray is used as part of the DGrid class, where the dimension names are crucial to its structure. The dimension names correspond to "Map" vectors, holding the actual values for that column of the array.

    Each array dimension carries with it its own projection information. The projection inforamtion takes the form of three integers: the start, stop, and stride values. This is clearest with an example. Consider a one-dimensional array 10 elements long. If the start value of the dimension constraint is 3, then the constrained array appears to be seven elements long. If the stop value is changed to 7, then the array appears to be five elements long. If the stride is changed to two, the array will appear to be 3 elements long. Array constraints are written as [start:stride:stop]. 

     A = [1 2 3 4 5 6 7 8 9 10]
 A[3::] = [4 5 6 7 8 9 10]
 A[3::7] = [4 5 6 7 8]
 A[3:2:7] = [4 6 8]
 A[0:3:9] = [1 4 7 10]

    NB: OPeNDAP uses zero-based indexing.

    See Also:
    DGrid, DVector, BaseType, Serialized Form

    • Field Detail

      • dimVector

        protected Vector<DArrayDimension> dimVector
        A Vector of DArrayDimension information (i.e. the shape)

    • Constructor Detail

      • DArray

        public DArray()
        Constructs a new DArray.

      • DArray

        public DArray​(String n)
        Constructs a new DArray with name n.
        Parameters:
        n - the name of the variable.

    • Method Detail

      • getTypeName

        public String getTypeName()
        Returns the OPeNDAP type name of the class instance as a String.
        Overrides:
        getTypeName in class DVector
        Returns:
        the OPeNDAP type name of the class instance as a String.

      • printDecl

        public void printDecl​(PrintWriter os,
                      String space,
                      boolean print_semi,
                      boolean constrained)
        Write the variable's declaration in a C-style syntax. This function is used to create textual representation of the Data Descriptor Structure (DDS). See The OPeNDAP User Manual for information about this structure.
        Overrides:
        printDecl in class DVector
        Parameters:
        os - The PrintWriter on which to print the declaration.
        space - Each line of the declaration will begin with the characters in this string. Usually used for leading spaces.
        print_semi - a boolean value indicating whether to print a semicolon at the end of the declaration.
        constrained - a boolean value indicating whether to print the declartion dependent on the projection information. This is only used by Server side code.
        See Also:
        BaseType.printDecl(PrintWriter, String, boolean)

      • printVal

        public void printVal​(PrintWriter pw,
                     String space,
                     boolean print_decl_p)
        Prints the value of the variable, with its declaration. This function is primarily intended for debugging OPeNDAP applications and text-based clients such as geturl.
        Overrides:
        printVal in class DVector
        Parameters:
        pw - the PrintWriter on which to print the value.
        space - this value is passed to the printDecl method, and controls the leading spaces of the output.
        print_decl_p - a boolean value controlling whether the variable declaration is printed as well as the value.
        See Also:
        BaseType.printVal(PrintWriter, String, boolean)

      • appendDim

        public void appendDim​(int size,
                      String name)
        Given a size and a name, this function adds a dimension to the array. For example, if the DArray is already 10 elements long, calling appendDim with a size of 5 will transform the array into a 10x5 matrix. Calling it again with a size of 2 will create a 10x5x2 array, and so on.
        Parameters:
        size - the size of the desired new dimension.
        name - the name of the new dimension.

      • appendDim

        public void appendDim​(int size)
        Add a dimension to the array. Same as appendDim(size, null).
        Parameters:
        size - the size of the desired new dimension.
        See Also:
        appendDim(int, String)

      • getDimensions

        public final Enumeration getDimensions()
        Returns an Enumeration of DArrayDimensions in this array.
        Returns:
        an Enumeration of DArrayDimensions in this array.

      • numDimensions

        public final int numDimensions()
        Returns the number of dimensions in this array.
        Returns:
        the number of dimensions in this array.

      • squeeze

        public void squeeze()
        Use this method to "squeeze" out all of the array dimensions whose size is equal to 1.
        Many queries that contstrain Arrays return an Array that has dimensions whose size has been reduced to 1. In effect that the dimension no longer really exists, except as a notational convention for tracking the hyperslab that the array represents. Since many clients have difficulty handling n-dimensional arrays this method was added to allow the client to easily "squeeze" the "extra" dimensions out of the array.

      • getFirstDimension

        public DArrayDimension getFirstDimension()
        Returns the DArrayDimension object for the first dimension.

      • printAsMapXML

        public void printAsMapXML​(PrintWriter pw,
                          String pad,
                          boolean constrained)