### Author Topic: -={ Challenge }=- Slope Gradient w/bonus question  (Read 1313 times)

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#### pkohut

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##### -={ Challenge }=- Slope Gradient w/bonus question
« on: July 18, 2010, 01:15:19 PM »
Determine the slope gradient of a collection of points (formula g(3) image)

Given a collection of points that represents a terrain area, find the slope gradient of the area.

Bonus question:
Find the standard deviation from the plane of best fit (formula g(4) image)

Quote
h(hat) notation is common in regression analysis to represent the predicted value based upon the regression equation, in this case:
h(hat) = a(x) + b(y) + c for each pair (x, y)

Test points:
Code: [Select]
`(setq pts '((0.0 0.0 3785.00)(20.0 0.0 3784.00)(40.0 0.0 3781.00)(60.0 0.0 3777.00)(80.0 0.0 3773.00)(0.0 20.0 3769.00)(20.0 20.0 3766.00)(40.0 20.0 3766.00)(60.0 20.0 3768.00)(80.0 20.0 3773.00)(0.0 40.0 3778.00)(20.0 40.0 3785.00)(40.0 40.0 3793.00)(60.0 40.0 3801.00)(80.0 40.0 3809.00)(0.0 60.0 3817.00)(20.0 60.0 3824.00)(40.0 60.0 3831.00)(60.0 60.0 3837.00)(80.0 60.0 3842.00)(0.0 80.0 3847.00)(20.0 80.0 3851.00)(40.0 80.0 3854.00)(60.0 80.0 3857.00)(80.0 80.0 3859.00)))`Slope Gradient (g3) = 1.05571
Standard deviation from plane of best fit (g4) = 13.33468
Values better be correct, I'm told the output results were certified as correct for the program I wrote.