From 33613a85afc4b1481367fbe92a17ee59c240250b Mon Sep 17 00:00:00 2001
From: Sven Eisenhauer <sven@sven-eisenhauer.net>
Date: Fri, 10 Nov 2023 15:11:48 +0100
Subject: add new repo

---
 .../Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp     | 167 +++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 Master/Modellbildung_und_Simulation/Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp

(limited to 'Master/Modellbildung_und_Simulation/Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp')

diff --git a/Master/Modellbildung_und_Simulation/Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp b/Master/Modellbildung_und_Simulation/Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp
new file mode 100644
index 0000000..97571f9
--- /dev/null
+++ b/Master/Modellbildung_und_Simulation/Aufgabenblatt1/DFTApp/src/DFTProcessor.cpp
@@ -0,0 +1,167 @@
+/*
+ * DFTProcessor.cpp
+ *
+ *  Created on: 29.04.2011
+ *      Author: sven
+ */
+#ifndef DFTPROCESSOR_H_
+	#include "DFTProcessor.h"
+#endif
+
+#ifndef _GLIBCXX_IOSTREAM
+	#include <iostream>
+#endif
+
+#ifndef _GLIBCXX_FSTREAM
+	#include <fstream>
+#endif
+
+#include <cmath>
+#include <string.h>
+#include <stdlib.h>
+#include <iomanip>
+
+const double PI = 3.14159265358979323846264338327950288419716939;
+
+const char* ORIG_FILENAME = "orig.wav";
+const char* IDFT_FILENAME = "idft.wav";
+
+DFTProcessor::DFTProcessor(DFTAppParameters& params)
+:mParams(params)
+,mNumDftSamples(mParams.getNumSamples() / 2)
+,mInputData(mParams.getNumSamples())
+,mRe(mNumDftSamples)
+,mIm(mNumDftSamples)
+,mIdft(mParams.getNumSamples())
+{
+	std::cout << "DFT processing " << mParams.getNumSamples() <<
+			" samples of" << mParams.getInputFilename() << std::endl;
+	std::ifstream inFile;
+	std::ofstream origFile;
+	std::ofstream idftFile;
+	inFile.open(mParams.getInputFilename().c_str(), std::ios::in | std::ios::binary);
+	origFile.open(ORIG_FILENAME, std::ios::out | std::ios::binary);
+	idftFile.open(IDFT_FILENAME, std::ios::out | std::ios::binary);
+	int dataStartOffset = 0x2C;
+	char header[dataStartOffset];
+	inFile.read(&header[0],dataStartOffset);
+	memcpy(&mSampleRate,((&header[0])+0x18),4);
+	origFile.write((char*) &header[0],dataStartOffset);
+	idftFile.write((char*) &header[0],dataStartOffset);
+	short data;
+	std::cout << "Original file:" << std::endl;
+	for (unsigned i=0;i<mParams.getNumSamples();i++)
+	{
+		inFile.read((char*) &data,sizeof(short));
+		mInputData.at(i) = (double) data;
+		origFile.write((char*) &data, sizeof(short));
+		if (i < 5) {
+			if (i != 0) {
+				std::cout << std::endl;
+			}
+			std::cout << mInputData.at(i);
+		}
+	}
+	inFile.close();
+	origFile.close();
+
+	double nd,id,Nd,xn;
+	Nd = (double) mParams.getNumSamples();
+	for (unsigned i = 0; i < mNumDftSamples; i++) {
+		id = (double) i;
+		mRe.at(i) = 0.0;
+		mIm.at(i) = 0.0;
+		for (unsigned n=0; n < mParams.getNumSamples(); n++) {
+			nd = (double) n;
+			xn = mInputData.at(n);
+			mRe.at(i) += xn * std::cos(2.0 * PI * nd * id / Nd );
+			mIm.at(i) += xn * std::sin(2.0 * PI * nd * id / Nd );
+		}
+		mIm.at(i) = -mIm.at(i);
+	}
+	std::cout << std::endl << "dft done" << std::endl;
+
+	// idft
+	double rex,imx,fd;
+	std::cout << "idft file:" << std::endl;
+	for (unsigned n=0 ; n<mParams.getNumSamples() ; n++)
+	{
+		nd = (double) n;
+		double reSum = 0.0;
+		double imSum = 0.0;
+		for (unsigned f=0; f < mNumDftSamples; f++)
+		{
+			fd = (double) f;
+			if (f == 0) {
+				rex = mRe.at(0) / Nd;
+			} else if (f == mNumDftSamples) {
+				rex = mRe.at(mNumDftSamples) / Nd;
+			} else {
+				rex = mRe.at(f) / (Nd / 2.0);
+			}
+			imx = - mIm.at(f) / (Nd / 2.0);
+			reSum += rex * std::cos(2.0 * PI * nd * fd / Nd);
+			imSum += imx * std::sin(2.0 * PI * nd * fd / Nd);
+		}
+		mIdft.at(n) = reSum + imSum;
+	}
+	for (unsigned n=0 ; n<mParams.getNumSamples(); n++) {
+		data = (short) round(mIdft.at(n));
+		idftFile.write((char*) &data, sizeof(short));
+		if (n < 5) {
+			if (n != 0) {
+				std::cout << std::endl;
+			}
+			double dout = mIdft.at(n);
+			std::cout << std::setprecision(16) <<  dout;
+		}
+	}
+	idftFile.close();
+	std::cout << std::endl << "idft done" << std::endl;
+
+	// amplitude spectrum
+	double A1, A2;
+	unsigned maxTimeDomFreq = mSampleRate / 2;
+	unsigned freqIntervalWidth = maxTimeDomFreq / mNumDftSamples;
+	for (unsigned f = 0 ; f < mNumDftSamples ; f++) {
+		A1 = mIm.at(f);
+		A2 = mRe.at(f);
+		SpectralData actSpecData;
+		actSpecData.mAmplitude = std::sqrt( (A1*A1) + (A2*A2) );
+		actSpecData.mPhase = std::atan(A2/A1);
+		actSpecData.mFreq = f * freqIntervalWidth;
+		mSpectrum.push_back(actSpecData);
+	}
+	writeSpectrumToCSV();
+	startGnuPlot();
+}
+
+DFTProcessor::~DFTProcessor() {
+	// TODO Auto-generated destructor stub
+}
+
+void DFTProcessor::writeSpectrumToCSV()
+{
+	std::ofstream csvFile;
+	csvFile.open("spectrum.csv", std::ios::out);
+	std::vector<SpectralData>::const_iterator specIter;
+	for(specIter = mSpectrum.begin() ; specIter != mSpectrum.end() ; specIter++) {
+		const SpectralData& actSpec = *specIter;
+		if (specIter != mSpectrum.begin()) {
+			csvFile << std::endl;
+		}
+		csvFile << actSpec.mFreq << ";";
+		csvFile << std::setprecision (12) << std::fixed << actSpec.mAmplitude;
+		csvFile << ";";
+		csvFile << std::setprecision (12) << std::fixed << actSpec.mPhase;
+	}
+	csvFile.close();
+}
+
+void DFTProcessor::startGnuPlot()
+{
+	int i = system("gnuplot spectrum.plt -p");
+	if (i != 0) {
+		std::cerr << "Error starting gnuplot: " << i << std::endl;
+	}
+}
-- 
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