4.5 _JT_ storage_ blocktridiaggeneral_ - general block-tridiagonal format

• Status: NOT IMPLEMENTED
• Current value: 4
• Also requires:

  Variable	Meaning	Value
  ia(_JT_ idim_)	leading dimension	3
  ia(_JT_ nrows_)	number of rows	2
  ia(_JT_ blocksize_)	size of blocks	7
  ia(_JT_ blocks_)	number of blocks	8

• Example:
  A = $$\left(\vphantom{ \begin{array}{ccccc} A_1 & C_1 & & & \\ B_1 ... .... & . & \\ & & . & . &C_{n-1} \\ & & &B_{n-1}& A_n \end{array} }\right.$$$$\begin{array}{ccccc} A_1 & C_1 & & & \\ B_1 & A_2 & C_2 & & \\ & . & . & . & \\ & & . & . &C_{n-1} \\ & & &B_{n-1}& A_n \end{array}$$ $$\left.\vphantom{ \begin{array}{ccccc} A_1 & C_1 & & & \\ B_1 ... .... & . & \\ & & . & . &C_{n-1} \\ & & &B_{n-1}& A_n \end{array} }\right)$$

  would be stored as:

  a = (A₁, A₂,..., A_n, B₁, B₂,..., B_{n - 1}, C₁, C₂,..., C_{n - 1})

  Note that the number of unknowns is equal to ia(_JT_ blocksize_) *ia(_JT_ blocks_) .