spec/gl-matrix/mat2-spec.js

/* Copyright (c) 2015, Brandon Jones, Colin MacKenzie IV.

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describe("mat2", function() {
    var mat2 = require("../../src/gl-matrix/mat2.js");

    var out, matA, matB, identity, result;

    beforeEach(function() {
        matA = [1, 2,
                3, 4];

        matB = [5, 6,
                7, 8];

        out =  [0, 0,
                0, 0];

        identity = [1, 0,
                    0, 1];
    });

    describe("create", function() {
        beforeEach(function() { result = mat2.create(); });
        it("should return a 4 element array initialized to a 2x2 identity matrix", function() { expect(result).toBeEqualish(identity); });
    });

    describe("clone", function() {
        beforeEach(function() { result = mat2.clone(matA); });
        it("should return a 4 element array initialized to the values in matA", function() { expect(result).toBeEqualish(matA); });
    });

    describe("copy", function() {
        beforeEach(function() { result = mat2.copy(out, matA); });
        it("should place values into out", function() { expect(out).toBeEqualish(matA); });
        it("should return out", function() { expect(result).toBe(out); });
    });

    describe("identity", function() {
        beforeEach(function() { result = mat2.identity(out); });
        it("should place values into out", function() { expect(result).toBeEqualish(identity); });
        it("should return out", function() { expect(result).toBe(out); });
    });

    describe("transpose", function() {
        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.transpose(out, matA); });

            it("should place values into out", function() { expect(out).toBeEqualish([1, 3, 2, 4]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.transpose(matA, matA); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([1, 3, 2, 4]); });
            it("should return matA", function() { expect(result).toBe(matA); });
        });
    });

    describe("invert", function() {
        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.invert(out, matA); });

            it("should place values into out", function() { expect(out).toBeEqualish([-2, 1, 1.5, -0.5]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.invert(matA, matA); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([-2, 1, 1.5, -0.5]); });
            it("should return matA", function() { expect(result).toBe(matA); });
        });
    });

    describe("adjoint", function() {
        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.adjoint(out, matA); });

            it("should place values into out", function() { expect(out).toBeEqualish([4, -2, -3, 1]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.adjoint(matA, matA); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([4, -2, -3, 1]); });
            it("should return matA", function() { expect(result).toBe(matA); });
        });
    });

    describe("determinant", function() {
        beforeEach(function() { result = mat2.determinant(matA); });

        it("should return the determinant", function() { expect(result).toEqual(-2); });
    });

    describe("multiply", function() {
        it("should have an alias called 'mul'", function() { expect(mat2.mul).toEqual(mat2.multiply); });

        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.multiply(out, matA, matB); });

            it("should place values into out", function() { expect(out).toBeEqualish([23, 34, 31, 46]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
            it("should not modify matB", function() { expect(matB).toBeEqualish([5, 6, 7, 8]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.multiply(matA, matA, matB); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([23, 34, 31, 46]); });
            it("should return matA", function() { expect(result).toBe(matA); });
            it("should not modify matB", function() { expect(matB).toBeEqualish([5, 6, 7, 8]); });
        });

        describe("when matB is the output matrix", function() {
            beforeEach(function() { result = mat2.multiply(matB, matA, matB); });

            it("should place values into matB", function() { expect(matB).toBeEqualish([23, 34, 31, 46]); });
            it("should return matB", function() { expect(result).toBe(matB); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });
    });

    describe("rotate", function() {
        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.rotate(out, matA, Math.PI * 0.5); });

            it("should place values into out", function() { expect(out).toBeEqualish([3, 4, -1, -2]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.rotate(matA, matA, Math.PI * 0.5); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([3, 4, -1, -2]); });
            it("should return matA", function() { expect(result).toBe(matA); });
        });
    });

    describe("scale", function() {
        var vecA;
        beforeEach(function() { vecA = [2, 3]; });

        describe("with a separate output matrix", function() {
            beforeEach(function() { result = mat2.scale(out, matA, vecA); });

            it("should place values into out", function() { expect(out).toBeEqualish([2, 4, 9, 12]); });
            it("should return out", function() { expect(result).toBe(out); });
            it("should not modify matA", function() { expect(matA).toBeEqualish([1, 2, 3, 4]); });
        });

        describe("when matA is the output matrix", function() {
            beforeEach(function() { result = mat2.scale(matA, matA, vecA); });

            it("should place values into matA", function() { expect(matA).toBeEqualish([2, 4, 9, 12]); });
            it("should return matA", function() { expect(result).toBe(matA); });
        });
    });

    describe("str", function() {
        beforeEach(function() { result = mat2.str(matA); });

        it("should return a string representation of the matrix", function() { expect(result).toEqual("mat2(1, 2, 3, 4)"); });
    });

   describe("frob", function() {
        beforeEach(function() { result = mat2.frob(matA); });
        it("should return the Frobenius Norm of the matrix", function() { expect(result).toEqual( Math.sqrt(Math.pow(1, 2) + Math.pow(2, 2) + Math.pow(3, 2) + Math.pow(4, 2))); });
   });

   describe("LDU", function() {
        beforeEach(function() {L = mat2.create(); D = mat2.create(); U = mat2.create(); result = mat2.LDU(L, D, U, [4,3,6,3]);
                               L_result = mat2.create(); L_result[2] = 1.5;
                               D_result = mat2.create();
                               U_result = mat2.create();
                               U_result[0] = 4; U_result[1] = 3; U_result[3] = -1.5;
                              });
        it("should return a lower triangular, a diagonal and an upper triangular matrix", function() {
            expect(result[0]).toBeEqualish(L_result);
            expect(result[1]).toBeEqualish(D_result);
            expect(result[2]).toBeEqualish(U_result);
        });
   });

});