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81 lines
1.5 KiB
Go
81 lines
1.5 KiB
Go
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// run
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// WARNING: GENERATED FILE - DO NOT MODIFY MANUALLY!
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// (To generate, in go/types directory: go test -run=Hilbert -H=2 -out="h2.src")
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// This program tests arbitrary precision constant arithmetic
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// by generating the constant elements of a Hilbert matrix H,
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// its inverse I, and the product P = H*I. The product should
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// be the identity matrix.
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package main
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func main() {
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if !ok {
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print()
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return
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}
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}
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// Hilbert matrix, n = 2
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const (
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h0_0, h0_1 = 1.0 / (iota + 1), 1.0 / (iota + 2)
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h1_0, h1_1
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)
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// Inverse Hilbert matrix
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const (
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i0_0 = +1 * b2_1 * b2_1 * b0_0 * b0_0
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i0_1 = -2 * b2_0 * b3_1 * b1_0 * b1_0
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i1_0 = -2 * b3_1 * b2_0 * b1_1 * b1_1
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i1_1 = +3 * b3_0 * b3_0 * b2_1 * b2_1
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)
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// Product matrix
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const (
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p0_0 = h0_0*i0_0 + h0_1*i1_0
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p0_1 = h0_0*i0_1 + h0_1*i1_1
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p1_0 = h1_0*i0_0 + h1_1*i1_0
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p1_1 = h1_0*i0_1 + h1_1*i1_1
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)
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// Verify that product is identity matrix
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const ok = p0_0 == 1 && p0_1 == 0 &&
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p1_0 == 0 && p1_1 == 1 &&
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true
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func print() {
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println(p0_0, p0_1)
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println(p1_0, p1_1)
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}
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// Binomials
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const (
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b0_0 = f0 / (f0 * f0)
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b1_0 = f1 / (f0 * f1)
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b1_1 = f1 / (f1 * f0)
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b2_0 = f2 / (f0 * f2)
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b2_1 = f2 / (f1 * f1)
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b2_2 = f2 / (f2 * f0)
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b3_0 = f3 / (f0 * f3)
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b3_1 = f3 / (f1 * f2)
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b3_2 = f3 / (f2 * f1)
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b3_3 = f3 / (f3 * f0)
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)
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// Factorials
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const (
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f0 = 1
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f1 = 1
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f2 = f1 * 2
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f3 = f2 * 3
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)
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