Re: Linear Interpolation problems

*To*: mathgroup at smc.vnet.net*Subject*: [mg102374] Re: [mg102359] Linear Interpolation problems*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Fri, 7 Aug 2009 05:30:08 -0400 (EDT)*Reply-to*: hanlonr at cox.net

ndp = 2; (* number of decimal places *) f = Interpolation[{{3, 20}, {10, 50}}, InterpolationOrder -> 1]; Table[{n, NumberForm[f[n] // N, {4, ndp}]}, {n, 3, 10}] {{3, "20.00"}, {4, "24.29"}, {5, "28.57"}, {6, "32.86"}, {7, "37.14"}, {8, "41.43"}, {9, "45.71"}, {10, "50.00"}} f = Interpolation[{ {{1, 3}, 20}, {{2, 3}, 30}, {{3, 3}, 60}, {{1, 10}, 50}, {{2, 10}, 55}, {{3, 10}, 25}}, InterpolationOrder -> 1]; m = Table[NumberForm[f[firm, year] // N, {4, ndp}], {firm, 3}, {year, 3, 10}] {{"20.00", "24.29", "28.57", "32.86", "37.14", "41.43", "45.71", "50.00"}, {"30.00", "33.57", "37.14", "40.71", "44.29", "47.86", "51.43", "55.00"}, {"60.00", "55.00", "50.00", "45.00", "40.00", "35.00", "30.00", "25.00"}} TableForm[m, TableHeadings -> {{"A", "B", "C"}, Range[3, 10]}] Bob Hanlon ---- kosal lee <leekosal at yahoo.com> wrote: ============= Hello, I am new to Mathematica. Please help me with linear interpolation problems. Thank you for your help. First, suppose I have two real values year earnings x = 3 f(x) = 20 x= 10 f(x) = 50 I want to have the interpolated values of f(4), f(5), to f(9) which is between actual values of f(3) and f(10). How can I do that with Mathematica? Second, suppose I have an excel spreadsheet having those above values for multiples firms as of the following firm f(3) f(10) A 20 50 B 30 55 C 60 25 I want to have the values of f(4) till f(9) as above and are stored in excel spreadsheet as of the following: firm f(3) f(4) f(5) ... (f9) f(10) A 20 50 B 30 55 C 60 25 Best Regards, Kosal