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Author Archives: dougaj4
Cubic Hermitic and Cardinal Splines
In my previous post on splines I described a quick and dirty approach to adjusting a cubic spline to fit monotonic data, which did not meet with universal approval, so I have followed up Mike Woodhouse’s link: (http://en.wikipedia.org/wiki/Monotone_cubic_interpolation) which gives a … Continue reading
Posted in Charts, Excel, Maths, UDFs, VBA
Tagged Cardinal spline, Cubic Hermitic spline, Cubic spline, Excel, monotonic hermitic spline, UDF, VBA
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The Ballad of Erica Levine
Two songs from Frankie Armstrong. The first is the Ballad of Erica Levine by Bob Blue, and the second, I’m Gonna be an Engineer by Peggy Seeger. Frankie was singing traditional folk songs in the UK in the 60’s and … Continue reading
Using Cubic Splines in Practice
I recently had an interesting query from Georg, a geography student in Germany regarding the use of cubic splines to fit a smooth curve to experimental data. The graph he sent me is shown below: The cubic spline has produced … Continue reading
Numerical solutions with CSpline
The CSpline function presented in a previous post fits a series of cubic polynomial curves to a specified series of points, returning the Y values for listed intermediate X values. I was recently asked if this could be reversed to … Continue reading
Posted in Excel, Maths, Newton, UDFs, VBA
Tagged Cubic spline, Excel, Numerical methods, solve equation, VBA
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More about not being different
Last year I posted a link to a puzzle at Tanya Khovanova’s Math Blog. I just came across a follow up to that puzzle: The Odder One Out where she discusses the responses. Which by some devious path reminded me … Continue reading
