REXS Specification

Scalar attribute values

The value of the attribute is specified in the "attribute" tag; e.g., <attribute …>4.72</attribute>.

The floating-point symbol is "." (period).

Array values

array

The "array" tag encloses the columns of a one-dimensional array.

c

The "c" (column) tag indicates a column of the array, and encloses a scalar entry of the array (see example below)

The floating-point symbol is "." (period).

code

If arrays exceed a certain size, it may be helpful to store them in binary format in the REXS file for performance reasons. The "code" xml attribute is an optional specification in the array tag. This should be used if the array is in binary format with base64 encoding in the REXS file. To do so, the encoding and the binary format are specified in the "array" xml tag. The byte order is "Little Endian." The following variants are available:

If the array is entered in binary format, the "c" tags are omitted.

Matrix values

matrix

The "matrix" tag encloses the rows of a matrix.

r

The "r" tag (row) identifies a row of the matrix, and encloses a list of "c" entries. The contents of all rows must be the same length.

c

The "c" tag (column) identifies a column of the matrix, and encloses a scalar entry of the matrix (see example below).

The floating-point symbol is "." (period).

code, rows, columns

If matrices exceed a certain size, it may be helpful to store them in binary format in the REXS file for performance reasons. The "code" xml attribute is an optional specification in the matrix tag. This should be used if the matrix is in binary format with base64 encoding in the REXS file. First, the 2d matrix is converted column-by-column into a 1d array (array = [column1, column2, ...]). This is then converted into binary format, as described above (the byte order is "Little Endian“) and finally converted into a string using base64 encoding. In addition to the binary format (int32, float64, float32), the number of rows and columns of the matrix must be specified via "rows" and "columns" in the matrix tag. The following variants are available:

If the matrix is entered in binary format, the "r" and "c" tags are omitted.

Array-of-array values

array_of_arrays

The "array_of_arrays" tag encloses the rows of an array-of-arrays.

array

The "array" tag identifies a row of the array-of-arrays, and encloses a list of "c" entries. The rows may be different lengths.

c

The "c" tag (column) identifies a column of an array, and encloses a scalar entry of the array-of-arrays (see example below).