1 // run 2 3 // Copyright 2015 The Go Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file. 6 7 // WARNING: GENERATED FILE - DO NOT MODIFY MANUALLY! 8 // (To generate, in go/types directory: go test -run=Hilbert -H=2 -out="h2.src") 9 10 // This program tests arbitrary precision constant arithmetic 11 // by generating the constant elements of a Hilbert matrix H, 12 // its inverse I, and the product P = H*I. The product should 13 // be the identity matrix. 14 package main 15 16 func main() { 17 if !ok { 18 print() 19 return 20 } 21 } 22 23 // Hilbert matrix, n = 2 24 const ( 25 h0_0, h0_1 = 1.0 / (iota + 1), 1.0 / (iota + 2) 26 h1_0, h1_1 27 ) 28 29 // Inverse Hilbert matrix 30 const ( 31 i0_0 = +1 * b2_1 * b2_1 * b0_0 * b0_0 32 i0_1 = -2 * b2_0 * b3_1 * b1_0 * b1_0 33 34 i1_0 = -2 * b3_1 * b2_0 * b1_1 * b1_1 35 i1_1 = +3 * b3_0 * b3_0 * b2_1 * b2_1 36 ) 37 38 // Product matrix 39 const ( 40 p0_0 = h0_0*i0_0 + h0_1*i1_0 41 p0_1 = h0_0*i0_1 + h0_1*i1_1 42 43 p1_0 = h1_0*i0_0 + h1_1*i1_0 44 p1_1 = h1_0*i0_1 + h1_1*i1_1 45 ) 46 47 // Verify that product is identity matrix 48 const ok = p0_0 == 1 && p0_1 == 0 && 49 p1_0 == 0 && p1_1 == 1 && 50 true 51 52 func print() { 53 println(p0_0, p0_1) 54 println(p1_0, p1_1) 55 } 56 57 // Binomials 58 const ( 59 b0_0 = f0 / (f0 * f0) 60 61 b1_0 = f1 / (f0 * f1) 62 b1_1 = f1 / (f1 * f0) 63 64 b2_0 = f2 / (f0 * f2) 65 b2_1 = f2 / (f1 * f1) 66 b2_2 = f2 / (f2 * f0) 67 68 b3_0 = f3 / (f0 * f3) 69 b3_1 = f3 / (f1 * f2) 70 b3_2 = f3 / (f2 * f1) 71 b3_3 = f3 / (f3 * f0) 72 ) 73 74 // Factorials 75 const ( 76 f0 = 1 77 f1 = 1 78 f2 = f1 * 2 79 f3 = f2 * 3 80 ) 81
