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fix : fixed segmentation fault error
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41eaa0fb49
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@ -37,49 +37,61 @@ namespace numerical_methods {
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* @returns p if n==1
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* @returns p if n==1
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* @returns y if n!=1
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* @returns y if n!=1
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*/
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*/
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std::complex<double> *FastFourierTransform(std::complex<double> *p,
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uint64_t n) {
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std::complex<double>* FastFourierTransform(std::complex<double>*p,uint64_t n)
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{
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if(n==1){
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return p; ///Base Case To return
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}
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double pi = 2 * asin(1.0); /// Declaring value of pi
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double pi = 2 * asin(1.0); /// Declaring value of pi
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if (n == 1) {
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auto om=std::complex<double>(cos(2*pi/n),sin(2*pi/n)); ///Calculating value of omega
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return p; /// Base Case To return
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auto *pe= new std::complex<double>[n/2]; /// Coefficents of even power
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auto *po= new std::complex<double>[n/2]; ///Coeeficents of odd power
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int k1=0,k2=0;
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for(int j=0;j<n;j++)
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{
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if(j%2==0){
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pe[k1++]=p[j]; ///Assigning values of even ceofficents
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}
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else po[k2++]=p[j]; ///Assigning value of odd coefficents
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}
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}
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auto om = std::complex<double>(
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auto *ye=FastFourierTransform(pe,n/2); ///Recursive Call
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cos(2 * pi / n), sin(2 * pi / n)); /// Calculating value of omega
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/// auto is used inplace of std::complex<double> to reduce complexity
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auto *yo=FastFourierTransform(po,n/2); ///Recursive Call
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auto *pe = new std::complex<double>[n / 2]; /// Coefficents of even power
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auto *po = new std::complex<double>[n / 2]; /// Coefficents of odd power
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auto *y=new std::complex<double>[n]; /// Final value representation list
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uint64_t k1 = 0, k2 = 0;
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k1=0,k2=0;
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for (uint64_t j = 0; j < n; j++) {
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if (j % 2 == 0) {
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for(int i=0;i<n/2;i++)
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pe[k1++] = p[j]; /// Assigning values of even coefficents
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{
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y[i]=ye[k1]+pow(om,i)*yo[k2]; /// Updating the first n/2 elements
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y[i+n/2]=ye[k1]-pow(om,i)*yo[k2];/// Updating the last n/2 elements
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k1++;
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k2++;
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} else
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po[k2++] = p[j]; /// Assigning value of odd coefficents
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}
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}
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auto *ye = FastFourierTransform(pe, n / 2); /// Recursive Call
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auto *yo = FastFourierTransform(po, n / 2); /// Recursive Call
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auto *y = new std::complex<double>[n]; /// Final value representation list
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for (uint64_t i = 0; i < n / 2; i++) {
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y[i] = ye[i] + pow(om, i) * yo[i]; /// Updating the first n/2 elements
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y[i + n / 2] =
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ye[i] - pow(om, i) * yo[i]; /// Updating the last n/2 elements
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}
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delete[] ye; /// Deleting dynamic array ye
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delete[] ye; /// Deleting dynamic array ye
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delete[] yo; /// Deleting dynamic array yo
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delete[] yo; /// Deleting dynamic array yo
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delete[] pe; /// Deleting dynamic array pe
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return y;
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delete[] po; /// Deleting dynamic array po
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return y; /// Returns the list
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}
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}
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} // namespace numerical_methods
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}/// namespace numerical_methods
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/**
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/**
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* @brief Self-test implementations
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* @brief Self-test implementations
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@ -87,22 +99,15 @@ std::complex<double> *FastFourierTransform(std::complex<double> *p,
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* in predicted and true value is less than 0.000000000001.
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* in predicted and true value is less than 0.000000000001.
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* @returns void
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* @returns void
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*/
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*/
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static void test() {
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static void test() {
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/* descriptions of the following test */
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/* descriptions of the following test */
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auto *t1 = new std::complex<double>[2]; /// Test case 1
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std::complex<double> t1[2]={1,2}; /// Test case 1
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t1[0] = {1, 0};
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std::complex<double> t2[4]={1,2,3,4}; /// Test case 2
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t1[1] = {2, 0};
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/// auto is used inplace of std::complex<double> to reduce complexity
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auto *t2 = new std::complex<double>[4]; /// Test case 2
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t2[0] = {1, 0};
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t2[1] = {2, 0};
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t2[2] = {3, 0};
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t2[3] = {4, 0};
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uint8_t n1 = sizeof(t1) / sizeof(std::complex<double>);
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uint8_t n2 = sizeof(t2) / sizeof(std::complex<double>);
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uint8_t n1 = 2;
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uint8_t n2 = 4;
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std::vector<std::complex<double>> r1 = {
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std::vector<std::complex<double>> r1 = {
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{3, 0}, {-1, 0}}; /// True Answer for test case 1
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{3, 0}, {-1, 0}}; /// True Answer for test case 1
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@ -128,10 +133,7 @@ static void test() {
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o2++;
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o2++;
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}
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}
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delete[] o1; /// Deleting dynamic array o1
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delete[] o2; /// Deleting dynamic array o2
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delete[] t1; /// Deleting dynamic array t1
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delete[] t2; /// Deleting dynamic array t2
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}
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}
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/**
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/**
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@ -141,7 +143,10 @@ static void test() {
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* calls automated test function to test the working of fast fourier transform.
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* calls automated test function to test the working of fast fourier transform.
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* @returns 0 on exit
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* @returns 0 on exit
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*/
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*/
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int main(int argc, char const *argv[]) {
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test(); // run self-test implementations
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int main(int argc, char const *argv[])
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{
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test();/// run self-test implementations
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return 0;
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return 0;
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}
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}
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