Re: Interpolation difficulty

*To*: mathgroup at smc.vnet.net*Subject*: [mg116569] Re: Interpolation difficulty*From*: Ray Koopman <koopman at sfu.ca>*Date*: Sun, 20 Feb 2011 05:25:26 -0500 (EST)*References*: <ijo544$lep$1@smc.vnet.net>

On Feb 19, 2:13 am, Javier <mathquesti... at gmail.com> wrote: > Interpolation[{{2, 1}, {4, 5}, {5, 2}}, InterpolationOrder -> 0] > gives a function which is 5 from 2 to 4, and 2 from 4 to 5. > > I want as a result a function which is 1 from 2 up to 4, then > 5 from 4 up to 5. It should extrapolate to x=1 giving also 1, > and to x=6 giving 2. Is this possible? Many thanks in advance. See the documentation for InterpolationOrder: http://reference.wolfram.com/mathematica/ref/InterpolationOrder.html It sounds like you were expecting Interpolation to interpret InterpolationOrder->0 the same way that ListLinePlot does. Also note that, when InterpolationOrder->0, the function returned by Interpolation disagrees with the data at the first data point.