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1. Calculation on first star facet example highlighted with pink

All calculation are performed in 2D. Model is projected on table facet plane

1.1 Draw line a through star facet edge belongs to table facet. Line will separate plane into half-planes β and δ:

1.2 Find most distant point (call it B) on star facet from line a.  A is point, where perpendicular from point B is crossing line a:

1.3 Find most distant point on girdle (call it D) from line a, point should belong to β half-plane. C is point, where perpendicular from point D is crossing line a:

1.4 Star ratio is |AB| length divided by |CD| length and transferred to percentage view. 

1.5 Upper ratio is equal to expression result (100% - Star ratio).

2. Calculation on second star facet example highlighted with pink

All calculation are performed in 2D. Model is projected on table facet plane

2.1 Draw line a through star facet edge belongs to table facet. Line will separate plane into half-planes β and δ:

2.2 Find most distant point (call it B) on star facet from line a.  A is point, where perpendicular from point B is crossing line a:

2.3 Find most distant point on girdle (call it D) from line a, point should belong to β half-plane. C is point, where perpendicular from point D is crossing line a:

2.4 Star ratio is |AB| length divided by |CD| length and transferred to percentage view. 

2.5 Upper ratio is equal to expression result (100% - Star ratio).

3. Star \ Upper ratio parameters in report

3.1 Star \ Upper ratio can be found in Main and Detailed Parameter part of full report, for example:

Main parameters:

Parameter

 

Avg

Min

Max

Dev

Star :

Upper ratio

%

61.39 :

38.61

53.29 :

46.71

71.25 :

28.75

17.96

Detailed parameters:

Parameter

 

1

2

3

4

5

6

7

8

Star :

Upper ratio

%

59.00 :

41.00

63.52 :

36.48

71.25 :

28.75

58.42 :

41.58

61.37 :

38.63

64.69 :

35.31

59.55 :

40.45

53.29 :

46.71

 

3.2 Following bookmark are used for Star ratio:

  • STAR_RATIO_PC
  • STAR_RATIO_PC_1 - STAR_RATIO_PC_8
  • STAR_RATIO_PC_DEV
  • STAR_RATIO_PC_MIN
  • STAR_RATIO_PC_MAX

3.3 Following bookmark are used for Upper ratio:

  • UPPER_RATIO_PC
  • UPPER_RATIO_PC_1 - UPPER_RATIO_PC_8
  • UPPER_RATIO_PC_DEV
  • UPPER_RATIO_PC_MIN
  • UPPER_RATIO_PC_MAX

3.4 Star \ Upper ratio can be found in following report types:

  • 8-Facet report
  • Full report
  • Illustrated report

3.5 Star \ Upper ratio is calculated for following cutting types:

  • Round brilliant (RBC)
  • Round fancies (oval, marquise, heart, pear and etc)
  • Cushion

4. Notes

  • If you have any question, please ask it in comments or send e-mail to developer.
  • If you find mistake, please describe it in comments or send e-mail to developer.
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