Compressed Base-Curve Chart Min/Max Values

[Haim Shlomo [Shamir]]

Dear Colleagues,

As you might already know from our previous conversations, Shamir is using in some cases more than one base per Rx range, where one considered to be the primary and the rest are secondary option.

Can we use the Min/Max values in the JSON format to describe the span of bases can be used for the specific Rx range, where the first column is the primary, the Min is the minimum secondary base and the Max is the maximum secondary base?

 

"AddMin": 0.75,
"AddMax": 4.00,
"Lines": [
              "-1200, 0, null",
              "-900, 0, 150, 50, 150",
              "-500, 0, 300, 150, 450",
              "-100, 0, 500, 300, 650",
                ......
                ]

Thanks for your reply.

Haim S.

[Steve Shanbaum]

Hi Haim,

Yes, this will get handled in the standard in the way you show.  The current description of the base curve chart line reads as (there are minor changes from your posted example with the naming):

The formatting of the compressed base curve chart within the Standard is as follows, using the example chart fragment from 6.1.  The Base Curve Chart object has an ID, and an array named ‘Adds’.  Adds is an array of objects, where each object contains the base curve chart values for a single add power.  The add power that applies is within the range specified between the ‘MinAdd’ and ‘MaxAdd’ values, inclusive.  For a single vision, the add power range will be 0.00 to 0.00.  The lines for that add power are in the ‘Lines’ array of strings, where each string corresponds to one record in the compressed base curve chart.  The sphere, cylinder, and base curve values are all represented as *100.  If the fourth and fifth values are not present in a given line (the base curve min and max recommended values), they are presumed to equal the third value.