Subroutines are presented in the order they are used when training the network.

`SUBROUTINE JNSEPA`

Sets the internal parameters and switches in common blocks`/JNINT2/`and`/JNINT3/`. If receptive fields are used, the defined geometries are checked for inconcistencies.`SUBROUTINE JNHEAD`

Writes a header on file number`MSTJN(6)`.`SUBROUTINE JNFEED`

Feeds the values in`OIN`through the network and calculates the values of the output nodes, without writing to`OUT`.`SUBROUTINE JNDELT`

Calculates the error from the output nodes and current values in`OUT`.`SUBROUTINE JNSATM`

Calculates the saturation measure**s**in eq. () for each layer.`JNSATM`is only called if`MSTJN(22)`0.`SUBROUTINE JNCHOP(ICHP)`

Switches on (`ICHP`**>**0) or off (`ICHP`**<**0) fixed precision weights, thresholds and sigmoid functions. If`ICHP`0 the current values of the weights and thresholds are chopped to the fixed precision. The bit precision is set by switches`MSTJN(28-30)`.`SUBROUTINE JNERR(IERR)`

If something goes wrong or if any inconcistensies are encountered during execution,`JNERR`is called and writes out an error message and stops the execution.`SUBROUTINE JNCOGR`

Controls the Conjugate Gradient training. It is called from`JNTRAL`if CG learning has been selected.`JNCOGR`calls the subroutines`JNCGBE`and`JNLINS`.`SUBROUTINE JNCGBE(BETAK,IOP)`

If`IOP`= 1,`JNCGBE`computes the CG momentum term in eq. () and returns it in`BETAK`.

If`IOP`= 0,`JNCGBE`sets`BETAK`= 0 and computes the scalar product of the current and previous gradients.`SUBROUTINE JNLINS`

Performs the line search with an algorithm that is a mixture of golden section search and quadratic interpolation. All parameters used in the line search are stored in the common block`/JNINT4/`.`SUBROUTINE JNSCGR`

Controls the Scaled Conjugate Gradient training. It calls the subroutine`JNCGBE`.`SUBROUTINE JNTRED`and`SUBROUTINE JNTQLI`

These routines are taken directly from [23] and are used to diagonalize the Hessian matrix and compute its eigenvectors and eigenvalues.

Fri Feb 24 11:28:59 MET 1995