RAVEL

Purpose:

Creates a multi-series table from one or more sources.

Syntax:

RAVEL(series1, series2, ..., seriesN)

seriesN

-

One or more series or tables.

 

Alternate Syntax:

RAVEL(series, length, start, overlap)

series

-

A series or multi-column table.

length

-

An integer, the length of each ravel segment.

start

-

Optional. An integer, the point in the series at which to begin splitting and copying.

overlap

-

Optional. An integer, the segment overlap. Defaults to 0.

Returns:

A multi-column table.

Example:

a = {1, 2, 3};

b = {1, 0, 1};

c = {9, 8, 7};

d = ravel(a, b, c);

 

creates a new array d where the columns of d are the series a, b and c.

 

d == {{1, 1, 9},

      {2, 0, 8}, 

      {3, 1, 7}} 

Example:

ravel(W1, W4..W6)

 

creates a multi-series table of Windows 1, 4, 5 and 6.

Example:

W1: ravel(1..9, 3)

 

returns the 3x3 table:

 

{{1, 4, 7},

 {2, 5, 8}, 

 {3, 6, 9}} 

Example:

ravel(W1, 100, 1, 10)

 

ravels the series in W1 into multiple 100 point long segments where each segment overlaps the previous segment by 10 points. The overlap parameter must be less than the segment length.

Example:

W1: {{1, 2}, {3, 4}}

W2: {{5, 6}, {7, 8}}

W3: concat(w1, w2)

W4: ravel(w1, w2)

 

W1 == {{1, 2},

       {3, 4}},

 

W2 == {{5, 6},

       {7, 8}}

 

W3 == {{1, 2},

       {3, 4},

       {5, 6},

       {7, 8}}

 

W4 == {{1, 2, 5, 6},

       {3, 4, 7, 8}}

 

CONCAT combines multi-column series on a column basis and RAVEL combines multi-column series on a row basis.

Remarks:

RAVEL is useful when performing iterative operation or the same operation on multiple series. RAVEL returns a multi-series table and many analysis functions operate in a column-oriented fashion, processing each column independently.

 

See RESHAPE to divide a series into columns of varying lengths.

 

See UNRAVEL to convert a table into a single column series.

 

See ITERATE for details on creating a SPL functions that operate on a column-oriented basis.

 

See CONCAT to combine tables on a column-by-column basis.

See Also:

.. (Range Specifier)

{} Array Construction

CONCAT

DECIMATE

EXTRACT

FLIPLR

INSERT

ITERATE

REMOVE

REPCOLUMN

REPLICATE

RESHAPE

SPECGRAM

UNRAVEL

WATERFALL