4.10 _JT_ storage_ ELLtranspose_ - ELLPACK-ITPACK transpose

• Status: NOT IMPLEMENTED
• Current value: 9
• Also requires:

  Variable	Meaning	Value
  ia(_JT_ idim_)	leading dimension	3
  ia(_JT_ nunk_)	number of unknowns	2
  ia(_JT_ maxnz_)	maximum number of non-zero elements in any column	4

• Description:

  This is the transpose of ELL storage. Here the coefficient is stored in an ia(_JT_ maxnz_) x ia(_JT_ nunk_) array, with main diagonal elements stored in the first row. A companion ia(_JT_ maxnz_) x ia(_JT_ nunk_) array maps the column in the reduced matrix to the column in the original matrix for each element.

  A = $$\left(\vphantom{ \begin{array}{ccccc} 11 & 0 & 0 & 14 & 15 \\ ... ...& 0 \\ 41 & 0 & 0 & 44 & 45 \\ 51 & 0 & 0 & 54 & 55 \end{array} }\right.$$$$\begin{array}{ccccc} 11 & 0 & 0 & 14 & 15 \\ 0 & 22 & 0 & 0 &... ...& 33 & 0 & 0 \\ 41 & 0 & 0 & 44 & 45 \\ 51 & 0 & 0 & 54 & 55 \end{array}$$ $$\left.\vphantom{ \begin{array}{ccccc} 11 & 0 & 0 & 14 & 15 \\ ... ...& 0 \\ 41 & 0 & 0 & 44 & 45 \\ 51 & 0 & 0 & 54 & 55 \end{array} }\right)$$

  would be represented in ELLT format by the arrays a and ja as follows:

  a = $$\left(\vphantom{ \begin{array}{ccccc} 11 & 22 & 33 & 44 & 55 \\ 14 & 0 & 0 & 41 & 51 \\ 15 & 0 & 0 & 45 & 54 \end{array} }\right.$$$$\begin{array}{ccccc} 11 & 22 & 33 & 44 & 55 \\ 14 & 0 & 0 & 41 & 51 \\ 15 & 0 & 0 & 45 & 54 \end{array}$$ $$\left.\vphantom{ \begin{array}{ccccc} 11 & 22 & 33 & 44 & 55 \\ 14 & 0 & 0 & 41 & 51 \\ 15 & 0 & 0 & 45 & 54 \end{array} }\right)$$    and    ja = $$\left(\vphantom{ \begin{array}{ccccc} 1 & 2 & 3 & 4 & 5 \\ 4 & 0 & 0 & 1 & 1 \\ 5 & 0 & 0 & 5 & 4 \end{array} }\right.$$$$\begin{array}{ccccc} 1 & 2 & 3 & 4 & 5 \\ 4 & 0 & 0 & 1 & 1 \\ 5 & 0 & 0 & 5 & 4 \end{array}$$ $$\left.\vphantom{ \begin{array}{ccccc} 1 & 2 & 3 & 4 & 5 \\ 4 & 0 & 0 & 1 & 1 \\ 5 & 0 & 0 & 5 & 4 \end{array} }\right)$$

  Note that the main diagonal elements must be in the first row of array a.