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Date/Time: Tue, 27 Feb 2024 01:10:40 +0000



[Programming Help] - Storing SCDateTime-data in a subgraph array?

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[2020-11-24 19:50:46]
kraut - Posts: 20
I am currently upgrading my old ACSIL code to Sierra Chart version 2200.

In my multi-timeframe helper class, I used to keep SCDateTime values as (float) in a subgraph array (sc.Subgraph[].Arrays[][]).

In Sierra Chart version 2200, is there a way to store SCDateTime data in subgraph arrays?

Update: How about casting the result of SCDateTime#GetAsDouble() to (float) and then storing it in a subgraph array? Would that only lose below-second resolution?
Date Time Of Last Edit: 2020-11-25 21:38:22
[2020-11-25 22:13:53]
kraut - Posts: 20
To answer my own question:

I just found out that the double floating point representation is the same as in Excel.

Therefore, the resolution of a date time value down-casted to float should have a precision up to an hour (100 years * 365 days * 24 hours = 876,000, i.e. 6 digits, which should be stored near full precision in a float variable). Minutes, however would not be guaranteed to be represented correctly.

The float range is 3.4E +/- 38 (7 digits).
[2023-03-18 23:04:56]
Tony - Posts: 445
I have the same issue. I found this in the SCDateTime Document: Working with the SCDateTime Variables and Values: GetAsDouble()

I guess a float number should be able to handle any date value (the integer portion):
(2023-1899) x 365 = 45260 days

It is just the time part, DataTimeValue.GetTimeInSeconds()/864000000 that the float number
doesn't have enough precision?

Right now, I have no problem get the accurate date, but the time has quite a few minutes
difference from Main Graph, wonder if there are any ways to get around this?
Date Time Of Last Edit: 2023-03-18 23:19:31
[2023-03-19 03:55:11]
Tony - Posts: 445
I found one of the possible solutions is to use 2 arrays of that subgraph, one for Date
and one for TimeInSeconds,

SCFloatArrayRef CustomDate = sc.Subgraph[0].Arrays[0];
SCFloatArrayRef CustomTimeInSeconds = sc.Subgraph[0].Arrays[1];

and to get the date and time for Index_N:


SCDateTime DT = 1.0 * CustomDate[Index_N] + 1.0*CustomTimeInSeconds[Index_N] / 86400.0;

It works, I am just hoping there is a simpler way of doing it.
Date Time Of Last Edit: 2023-03-22 15:15:46

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