MTDATA – Phase Diagram Software from the National Physical Laboratory

 

 

 

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COMPUTE

Function:

initiates the computation of the predominance area diagram. Output is sent both to the screen and to a file. Overconstrained areas can be detected and excluded from further consideration. Labelling is optional.

Parameters:

labels

zero_pass

lgt_p_max

lgt_m_max

Defaults:

zero_pass = default

labels = all

Examples:

compute !

compute zero_pass = none !

compute zero_pass = mark labels = no !

compute lgt_p_max = 2 !

Parameter values:

Most parameters within the COMPUTE command deal with the management of the mathematical methods used in the calculation. The default values set by the program will usually suffice. However, four settings are of particular interest:

LABELS

takes the values YES/NONE

YES  - both predominance areas and overconstrained regions are labelled.

NO - no areas are labelled.

ZERO_PASS

takes the values DEFAULT/ CUT_ONLY/ MARK_ONLY/ NONE

DEFAULT - has the effect of CUT and MARK together. Pass zero delineates with broken lines regions of over-constraint caused by various compounds and excludes over-constrained regions from further consideration, demarking their outer boundaries with a solid line.

CUT_ONLY - pass zero excludes overconstrained areas demarking them with solid line.

MARK_ONLY - pass zero indicates with broken lines regions of over-constraint caused by various compounds.

NONE - no pass zero.

General comments:

Normally it will be unnecessary to change the default options in COMPUTE. However, for purposes of preparing reports it may be desirable to prepare COPLOTs with and without labelling and with and without exclusion of overconstrained regions. No provision for labelling with substance names is provided; one possibility is to cut substance names from the substance list and stick these on a COPLOT prepared with LABELS = NONE. A better method is to create a METAFILE for subsequent plotting using the UTILITY module.
    
The operation of the zeroth pass can also be controlled by means of CLASSIFY. If compounds of Type 2 and Type 3 components are classified as ABSENT they cannot overconstrain part of the diagram.

 

Updated 6 July 2010