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# Slope

Hello,

I am trying to find the linear regression of weight gain over time via MS SQL Server.  I found a function for slope and im trying to apply it.  I am looking for a conformation on this equation and if im applying it correctly.

Slope = ( COUNT(*)*SUM(x*y) -SUM(x)*SUM(y) ) / (COUNT(*)*SUM(x^2)-SUM(x)^2)

The site i found it said x is date and y is weight.  I figured (correct me if im wrong) that x would be the age of the bird in days so i came up with the following query....

SELECT
(COUNT(*)*SUM(Cast(DateDiff(dd, [Hatch Date], [Date]) As Float)*Weight) -SUM(Cast(DateDiff(dd, [Hatch Date], [Date]) As Float))*SUM(Weight) ) / (COUNT(*)*SUM(Cast(DateDiff(dd, [Hatch Date], [Date]) As Float)^2)-SUM(Cast(DateDiff(dd, [Hatch Date], [Date]) As Float))^2)
FROM
WingbandFlock As wf
INNER JOIN
Weight As w
ON
wf.[Bird ID] = w.[Bird ID]

In concept, am i correct?  I am still running into an SQL error i have not solved, if you know that you can post the answer in my related question for more points :)

http://www.experts-exchange.com/Databases/Microsoft_SQL_Server/Q_22077814.html#a18045854

Thanks!

-Navicerts
0
Navicerts
1 Solution

Commented:
I thought ^ in SQL meant xor, not power
0

Author Commented:
Well shoot, that explains some things.  Working now!  Sorry i *thought* it was a math question, but you answered an SQL Server question :)  I graphed it and the answer checks out too.

Thanks again!

SELECT
(Count(*)*SUM(Cast([Feed Consumed] As float)*([Weight Gain]*453.6)) -SUM(Cast([Feed Consumed] As float))*SUM(([Weight Gain]*453.6)) ) / (Count(*)*SUM(power(Cast([Feed Consumed] As float),2))-power(SUM(Cast([Feed Consumed] As float)), 2))
FROM
WingbandFlock As wf
INNER JOIN
[Feed Consumed] As fc
ON
wf.[Bird ID] = fc.[Bird ID]
INNER JOIN
[Keepers Report] As kr
ON
wf.[Bird ID] = kr.[Bird ID]
0
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