imdd_silas/Tests/00_signals/Signal_test.m

classdef Signal_test < IMDDTestCase
    methods (Test, TestTags = {'unit', 'fast', 'signals'})
        function constructorStoresSignalAndSamplingRate(testCase)
            sig = Signal([1; 2; 3], "fs", 64e9);

            testCase.verifyEqual(sig.signal, [1; 2; 3]);
            testCase.verifyEqual(sig.fs, 64e9);
            testCase.verifyEmpty(sig.logbook);
        end

        function arithmeticOperatorsSupportSignalOperands(testCase)
            x = Signal([1; 2; 3]);
            y = Signal([4; 5; 6]);

            sumSig = x + y;
            diffSig = y - x;
            prodSig = x .* y;

            testCase.verifyEqual(sumSig.signal, [5; 7; 9]);
            testCase.verifyEqual(diffSig.signal, [3; 3; 3]);
            testCase.verifyEqual(prodSig.signal, [4; 10; 18]);
        end

        function arithmeticOperatorsSupportNumericOperands(testCase)
            x = Signal([1; 2; 3]);

            sumSig = x + 2;
            diffSig = x - 1;
            prodSig = x .* 3;

            testCase.verifyEqual(sumSig.signal, [3; 4; 5]);
            testCase.verifyEqual(diffSig.signal, [0; 1; 2]);
            testCase.verifyEqual(prodSig.signal, [3; 6; 9]);
        end

        function lengthReturnsSignalLength(testCase)
            sig = Signal(zeros(11, 1));

            testCase.verifyEqual(sig.length(), 11);
        end

        function normalizeRmsScalesSignalToUnitPower(testCase)
            sig = Signal([1; -1; 1; -1]);

            sig = sig.normalize("mode", normalization_mode.rms);

            testCase.verifyEqual(mean(abs(sig.signal).^2), 1, "AbsTol", 1e-12);
        end

        function normalizeOneOneMapsSignalToMinusOneToOne(testCase)
            sig = Signal([2; 4; 6]);

            sig = sig.normalize("mode", normalization_mode.oneone);

            testCase.verifyEqual(sig.signal, [-1; 0; 1], "AbsTol", 1e-12);
        end

        function logbookEntryAppendsRowAndDescription(testCase)
            sig = Signal([1; 0; -1], "fs", 1);

            sig = sig.logbookentry("unit-test entry", sig);

            testCase.verifyEqual(height(sig.logbook), 1);
            testCase.verifyEqual(string(sig.logbook.SignalType(1)), "Signal");
            testCase.verifyEqual(string(sig.logbook.Description(1)), "unit-test entry");
            testCase.verifyEqual(string(sig.logbook.ModifierName(1)), "Signal");
        end

        function resampleWithIdenticalRatesKeepsSignalAndFs(testCase)
            original = [1; 2; 3; 4];
            sig = Signal(original, "fs", 8);

            sig = sig.resample("fs_in", 8, "fs_out", 8);

            testCase.verifyEqual(sig.signal, original);
            testCase.verifyEqual(sig.fs, 8);
            testCase.verifyEqual(height(sig.logbook), 1);
        end

        function resampleToNewRateUpdatesSamplingRate(testCase)
            sig = Signal((1:8).', "fs", 8);

            sig = sig.resample("fs_in", 8, "fs_out", 16);

            testCase.verifyEqual(sig.fs, 16);
            testCase.verifyNotEmpty(sig.signal);
            testCase.verifyEqual(height(sig.logbook), 1);
        end

        function spectrumCanUseSamplingRateNormalizedFrequencyAxis(testCase)
            fig = figure("Visible", "off");
            cleanup = onCleanup(@() close(fig));
            fignum = fig.Number;

            sig = Signal(randn(4096, 1), "fs", 8e9);

            sig.spectrum( ...
                "fignum", fignum, ...
                "normalizeToSamplingRate", 1, ...
                "normalizeTo0dB", 1, ...
                "fft_length", 512);

            ax = findobj(fig, "Type", "Axes");
            lineObj = findobj(ax, "Type", "Line");

            testCase.verifyEqual(ax.XLim, [-0.5 0.5], "AbsTol", 1e-12);
            testCase.verifyEqual(string(ax.XLabel.String), "Normalized Frequency f/fs");
            testCase.verifyGreaterThanOrEqual(min(lineObj.XData), -0.5);
            testCase.verifyLessThanOrEqual(max(lineObj.XData), 0.5);
            testCase.verifyLessThanOrEqual(abs(min(lineObj.XData) + 0.5), 1/512);
            testCase.verifyLessThanOrEqual(abs(max(lineObj.XData) - 0.5), 1/512);
        end

        function spectrumCanShowOneSidedSamplingRateNormalizedAxis(testCase)
            fig = figure("Visible", "off");
            cleanup = onCleanup(@() close(fig));
            fignum = fig.Number;

            sig = Signal(randn(4096, 1), "fs", 8e9);

            sig.spectrum( ...
                "fignum", fignum, ...
                "normalizeToSamplingRate", 1, ...
                "show_onesided", true, ...
                "normalizeTo0dB", 1, ...
                "fft_length", 512);

            ax = findobj(fig, "Type", "Axes");
            lineObj = findobj(ax, "Type", "Line");

            testCase.verifyEqual(ax.XLim, [0 0.5], "AbsTol", 1e-12);
            testCase.verifyGreaterThanOrEqual(min(lineObj.XData), 0);
            testCase.verifyLessThanOrEqual(max(lineObj.XData), 0.5);
            testCase.verifyLessThanOrEqual(abs(max(lineObj.XData) - 0.5), 1/512);
        end

        function castingRoundTripPreservesSignalThroughAllDomains(testCase)
            infoIn = Informationsignal([0; 1; 1; 0]);

            elecFromInfo = infoIn.Electricalsignal("fs", 64e9, "logbook", infoIn.logbook);
            optFromElec = elecFromInfo.Opticalsignal( ...
                "fs", elecFromInfo.fs, ...
                "logbook", elecFromInfo.logbook, ...
                "lambda", 1310e-9, ...
                "nase", 0, ...
                "polrot", 0);
            elecFromOpt = optFromElec.Electricalsignal("fs", optFromElec.fs, "logbook", optFromElec.logbook);
            infoOut = elecFromOpt.Informationsignal("fs", elecFromOpt.fs, "logbook", elecFromOpt.logbook);

            testCase.verifyClass(elecFromInfo, 'Electricalsignal');
            testCase.verifyClass(optFromElec, 'Opticalsignal');
            testCase.verifyClass(elecFromOpt, 'Electricalsignal');
            testCase.verifyClass(infoOut, 'Informationsignal');

            testCase.verifyEqual(infoOut.signal, infoIn.signal);
            testCase.verifyEqual(elecFromInfo.fs, 64e9);
            testCase.verifyEqual(optFromElec.fs, 64e9);
            testCase.verifyEqual(elecFromOpt.fs, 64e9);
            testCase.verifyEqual(infoOut.fs, 64e9);
            testCase.verifyEqual(optFromElec.lambda, 1310e-9);
            testCase.verifyEqual(optFromElec.nase, 0);
        end
    end
end