Colin Sell Colin Sell Colin Sell (born 1 December 1948) is a British pianist who has appeared on the radio panel games "Whose Line Is It Anyway?" and "I'm Sorry I Haven't a Clue". He has become famous mostly for his long service on the latter show, where the opening credits are "At the piano is Colin Sell, and your chairman is Humphrey Lyttelton/Jack Dee", in the manner of the show none of the panelists are credited in the opening credits, but are introduced by the chairman, usually in a sarcastic manner ("the foremost available comedians. I'm sorry. The four "most available"
I-spline I-spline In the mathematical subfield of numerical analysis, an I-spline is a monotone spline function. A family of "I-spline" functions of degree "k" with "n" free parameters is defined in terms of the M-splines "M"("x"|"k", "t") where "L" is the lower limit of the domain of the splines. Since M-splines are non-negative, "I-splines" are monotonically non-decreasing. Let "j" be the index such that "t" ≤ "x" < "t". Then "I"("x"|"k", "t") is zero if "i" > "j", and equals one if "j" − "k" + 1 > "i". Otherwise, "I-splines" can be used as basis splines for regression analysis and