github.com/consensys/gnark-crypto@v0.14.0/ecc/bls12-381/fr/polynomial/multilin_test.go (about)

     1  // Copyright 2020 Consensys Software Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Code generated by consensys/gnark-crypto DO NOT EDIT
    16  
    17  package polynomial
    18  
    19  import (
    20  	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
    21  	"github.com/leanovate/gopter"
    22  	"github.com/leanovate/gopter/gen"
    23  	"github.com/leanovate/gopter/prop"
    24  	"github.com/stretchr/testify/assert"
    25  	"testing"
    26  )
    27  
    28  // TODO: Property based tests?
    29  func TestFoldBilinear(t *testing.T) {
    30  
    31  	for i := 0; i < 100; i++ {
    32  
    33  		// f = c₀ + c₁ X₁ + c₂ X₂ + c₃ X₁ X₂
    34  		var coefficients [4]fr.Element
    35  		for i := 0; i < 4; i++ {
    36  			if _, err := coefficients[i].SetRandom(); err != nil {
    37  				t.Error(err)
    38  			}
    39  		}
    40  
    41  		var r fr.Element
    42  		if _, err := r.SetRandom(); err != nil {
    43  			t.Error(err)
    44  		}
    45  
    46  		// interpolate at {0,1}²:
    47  		m := make(MultiLin, 4)
    48  		m[0] = coefficients[0]
    49  		m[1].Add(&coefficients[0], &coefficients[2])
    50  		m[2].Add(&coefficients[0], &coefficients[1])
    51  		m[3].
    52  			Add(&m[1], &coefficients[1]).
    53  			Add(&m[3], &coefficients[3])
    54  
    55  		m.Fold(r)
    56  
    57  		// interpolate at {r}×{0,1}:
    58  		var expected0, expected1 fr.Element
    59  		expected0.
    60  			Mul(&r, &coefficients[1]).
    61  			Add(&expected0, &coefficients[0])
    62  
    63  		expected1.
    64  			Mul(&r, &coefficients[3]).
    65  			Add(&expected1, &coefficients[2]).
    66  			Add(&expected0, &expected1)
    67  
    68  		if !m[0].Equal(&expected0) || !m[1].Equal(&expected1) {
    69  			t.Fail()
    70  		}
    71  	}
    72  }
    73  
    74  func TestPrecomputeLagrange(t *testing.T) {
    75  
    76  	testForDomainSize := func(domainSize uint8) bool {
    77  		polys := computeLagrangeBasis(domainSize)
    78  
    79  		for l := uint8(0); l < domainSize; l++ {
    80  			for i := uint8(0); i < domainSize; i++ {
    81  				var I fr.Element
    82  				I.SetUint64(uint64(i))
    83  				y := polys[l].Eval(&I)
    84  
    85  				if i == l && !y.IsOne() || i != l && !y.IsZero() {
    86  					t.Errorf("domainSize = %d: p_%d(%d) = %s", domainSize, l, i, y.Text(10))
    87  					return false
    88  				}
    89  			}
    90  		}
    91  		return true
    92  	}
    93  
    94  	t.Parallel()
    95  	parameters := gopter.DefaultTestParameters()
    96  
    97  	parameters.MinSuccessfulTests = int(maxLagrangeDomainSize)
    98  
    99  	properties := gopter.NewProperties(parameters)
   100  
   101  	properties.Property("l'th lagrange polynomials must evaluate to 1 on l and 0 on other values in the domain", prop.ForAll(
   102  		testForDomainSize,
   103  		gen.UInt8Range(2, maxLagrangeDomainSize),
   104  	))
   105  
   106  	properties.TestingRun(t, gopter.ConsoleReporter(false))
   107  }
   108  
   109  // TODO: Benchmark folding? Algorithms is pretty straightforward; unless we want to measure how well memory management is working
   110  
   111  func TestFoldedEqTable(t *testing.T) {
   112  	q := make([]fr.Element, 2)
   113  	q[0].SetInt64(2)
   114  	q[1].SetInt64(3)
   115  
   116  	m := make(MultiLin, 4)
   117  	m[0].SetOne()
   118  	m.Eq(q)
   119  
   120  	eq := make([]fr.Element, 4)
   121  	p := make([]fr.Element, 2)
   122  
   123  	var one fr.Element
   124  	one.SetOne()
   125  
   126  	for p0 := 0; p0 < 2; p0++ {
   127  		p[1].SetZero()
   128  		for p1 := 0; p1 < 2; p1++ {
   129  			eq[p0*2+p1] = EvalEq(q, p)
   130  			p[1].Add(&p[1], &one)
   131  		}
   132  		p[0].Add(&p[0], &one)
   133  	}
   134  
   135  	for i := 0; i < 4; i++ {
   136  		assert.Equal(t, eq[i], m[i], "folded table disagrees with EqEval", i)
   137  	}
   138  
   139  }