[This message was posted by Rolf Andersson of Pantor Engineering <[email protected]> to the "FAST Protocol" discussion forum at http://fixprotocol.org/discuss/46. You can reply to it on-line at http://fixprotocol.org/discuss/read/6786587d - PLEASE DO NOT REPLY BY MAIL.]
Shashank, the mantissa is not present if the exponent is NULL. (Section 10.6.2: "If a scaled number is nullable, the exponent is nullable and the mantissa is non-nullable. A NULL scaled number is represented as a NULL exponent. The mantissa is present in the stream iff the exponent is not NULL.") Best, Rolf > Hi Dale, > > Thanks for reply. > > I want some clarification, still I am not clear. > > According to spec ~ "6.2.2 Decimal Field Instructions: If the decimal > field has optional presence and has INDIVIDUAL OPERATORS, the presence > of the mantissa is dependent on the presence of the exponent." and > "10.5.1 Presence Map and NULL Utilization: Decimal fields with > individual operators have the following utilization: • If the decimal > has mandatory presence, the exponent and mantissa fields are treated as > two separate mandatory integer fields as described above. • If the > decimal has optional presence, the exponent field is treated as an > optional integer field and the mantissa field is treated as a mandatory > integer field. The presence of the mantissa field and any related bits > in the presence map are dependent on the presence of the exponent. The > mantissa field appears in the stream iff the exponent value is > considered present. If the mantissa has an operator that requires a bit > in the presence map, this bit is present iff the exponent value is > considered present." > > I am some what clear with "Decimal fields with individual operators" > > According to my given example: > > (decimal id="1" presence="optional" name="Price") (copy/) (/decimal) > > I have a single field operator for decimal field instruction. > > For "Decimal field with single field operator", my understanding is: > 1. Both Exponent and mantissa will be treated as "optional" field. > (Am I right? Or always Mantissa will be treated as Mandatory. > According to spec, mantissa field is treated as a mandatory > integer field, if Decimal is having individual operators and > presence of decimal is optional) > > 2. The presence of the mantissa does not depend on the presence of the > exponent. (As there is no individual field operator). Am I right here? > > So, in case of "Decimal with single field operator", > > Sequence 1: (Sender want to send 9427.55) PMAP Bit will be '1' Encoded > value will be in form of exponent and mantissa: Sender will send > Exponent as "-2" and Mantissa as "942755". Receiver will expect two > fields (Exponent and Mantissa) in FAST Format. Here presence of Mantissa > does not depend on presence of exponent (as single field operator) Wire > representation for complete decimal field will be: 0xFE 0x39 0x45 0xA3 > > Sequence 2: (Sender want to send NULL) PMAP Bit will be '1' The combined > decoded decimal value should be "NULL". Here presence of Mantissa does > not depend on presence of exponent (as single field operator) Receiver > will expect two fields (Exponent and Mantissa) in FAST Format. whether > Sender will send only one NULL (0x80) for exponent; or two NULL (0x80 > 0x80) for exponent and mantissa??? > > Thanks & regards Shashank [You can unsubscribe from this discussion group by sending a message to mailto:[email protected]] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Financial Information eXchange" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/fix-protocol?hl=en -~----------~----~----~----~------~----~------~--~---
