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 Split Value and Convert Hex to Decimal Rate Topic Display Mode Topic Options
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 Posted Tuesday, August 19, 2014 12:13 PM
 Grasshopper Group: General Forum Members Last Login: Tuesday, September 9, 2014 12:51 PM Points: 12, Visits: 50
 Hi everyone,I have been task to decode a very long Hex string to decimal for further analysis. The output I'm told should be two (2) columns between 2,000 to 3,000 rows of decimals values. My issues are the following...1. I don't know what the split value is2. I am told the values are 32 bit floating data array but I don't think it is.3. The hex are supposedly 4 characters to it decimal value. for example: 1001: 5.741E-42 0100: 3.59E-43 CD44: 7.3635E-414. Number 3 would only make sense if the values i'm told is 16 bit float and not 32.I apologize in advance if this seemed confusing.Thanks.
Post #1605098
 Posted Monday, September 8, 2014 4:02 AM
 Say Hey Kid Group: General Forum Members Last Login: Wednesday, February 11, 2015 1:42 AM Points: 661, Visits: 292
 agbondoc (8/19/2014)Hi everyone,I have been task to decode a very long Hex string to decimal for further analysis. The output I'm told should be two (2) columns between 2,000 to 3,000 rows of decimals values. My issues are the following...1. I don't know what the split value is2. I am told the values are 32 bit floating data array but I don't think it is.3. The hex are supposedly 4 characters to it decimal value. for example: 1001: 5.741E-42 0100: 3.59E-43 CD44: 7.3635E-414. Number 3 would only make sense if the values i'm told is 16 bit float and not 32.I apologize in advance if this seemed confusing.Thanks.Your description is very vauge and it is hard to understand what you are after.First: All hex numbers in your example are two bytes (it takes 2 hex digits to represent one byte).So before you can go on, you need to know exactly how the data is formatted; is it decimal/float/... , 16 bit/32 bit/...Since you are asking your question in this forum, I assume you are looking for a SQL solution. Based on the information in your query I just have to guess what you are after, but I will give a short sample, that might give you some direction on how the problem can be solved.In this short example I take data stored as a SQL "binary" and spilt it in 4-byte chunks, which are then converted into float:`-- CREATE A FUNCTION TO CONVERT BINARY TO FLOAT-- (code from: http://ask.sqlservercentral.com/questions/43447/how-do-i-convert-a-hex-to-a-floating-point-number.html)CREATE FUNCTION dbo.fnBinaryReal2Real( @BinaryFloat BINARY(4)) RETURNS REAL AS BEGIN DECLARE @Mantissa REAL, @Exponent SMALLINT, @IntValue INT, @Real2 REAL SELECT @Real2 = CAST(2.0 AS REAL), @IntValue = CAST(@BinaryFloat AS INT), @Exponent = (@IntValue & 0x7f800000) / 0x00800000, @Mantissa = 1.0 + (@IntValue & 0x007FFFFF) * POWER(@Real2, -23) RETURN SIGN(@IntValue) * @Mantissa * POWER(@Real2, @Exponent - 127) ENDGO-- CREATE A TALLY TABLE-- (code from: http://www.sqlservercentral.com/articles/T-SQL/62867/)IF OBJECT_ID('dbo.Tally') IS NOT NULL DROP TABLE dbo.Tally--===== Create and populate the Tally table on the flySELECT TOP 11000 --equates to more than 30 years of dates IDENTITY(INT,1,1) AS NINTO dbo.TallyFROM Master.dbo.SysColumns sc1, Master.dbo.SysColumns sc2-- GET THE BINARY DATAdeclare @data binary(12)set @data = cast(0x40490FDB3FB504F342280000 as binary(12))-- "LOOP" OVER THE BINARY STRING USING A TALLY TABLEselect dbo.fnBinaryReal2Real(substring(@data, (n-1) * 4 + 1, 4))from Tallywhere n <= len(@data) / 4`Your question indicates that your data might be represented as a string. If that is the case, you can have a look att this page to see how to convert that into binary:http://blogs.msdn.com/b/sqltips/archive/2008/07/02/converting-from-hex-string-to-varbinary-and-vice-versa.aspxGood luck!/M
Post #1611374
 Posted Monday, September 8, 2014 5:48 PM
 Grasshopper Group: General Forum Members Last Login: Tuesday, September 9, 2014 12:51 PM Points: 12, Visits: 50
 Thanks for for responding to my query.I completely understand where you are coming from. My issue is I don't have a lot of information and I have been asked to solve and convert this "mystery" hex string.The other issue is proprietary. I get no cooperation from the people that built the db (sql) and so doing a reverse engineering is a little more challenging.With that said, I think your solution might work. Thanks.
Post #1611615
 Posted Monday, September 8, 2014 10:45 PM
 Hall of Fame Group: General Forum Members Last Login: Today @ 5:05 AM Points: 3,829, Visits: 9,932
 agbondoc (8/19/2014)Hi everyone,I have been task to decode a very long Hex string to decimal for further analysis. The output I'm told should be two (2) columns between 2,000 to 3,000 rows of decimals values. My issues are the following...1. I don't know what the split value is2. I am told the values are 32 bit floating data array but I don't think it is.3. The hex are supposedly 4 characters to it decimal value. for example: 1001: 5.741E-42 0100: 3.59E-43 CD44: 7.3635E-414. Number 3 would only make sense if the values i'm told is 16 bit float and not 32.I apologize in advance if this seemed confusing.Thanks.Quick question, do you have any means of asserting the correctness of the output?
Post #1611640
 Posted Tuesday, September 9, 2014 12:58 PM
 Grasshopper Group: General Forum Members Last Login: Tuesday, September 9, 2014 12:51 PM Points: 12, Visits: 50
 Hi Eirikur,I do, actually. There is a UI that gives me the data in decimal as an output, e.g. 1.234.
Post #1611931

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