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fix : fixed segmentation fault error

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Ameya Chawla 2021-10-22 09:55:19 +05:30 committed by GitHub
parent 41eaa0fb49
commit 5c1c4a4a3e
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1 changed files with 56 additions and 51 deletions
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107
numerical_methods/fast_fourier_transform.cpp
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@ -37,49 +37,61 @@ namespace numerical_methods {
* @returns p if n==1
* @returns y if n!=1
*/
std::complex<double> *FastFourierTransform(std::complex<double> *p,
uint64_t n) {
double pi = 2 * asin(1.0); /// Declaring value of pi
if (n == 1) {
return p; /// Base Case To return
}
std::complex<double>* FastFourierTransform(std::complex<double>*p,uint64_t n)
{
auto om = std::complex<double>(
cos(2 * pi / n), sin(2 * pi / n)); /// Calculating value of omega
if(n==1){
return p; ///Base Case To return
}
/// auto is used inplace of std::complex<double> to reduce complexity
auto *pe = new std::complex<double>[n / 2]; /// Coefficents of even power
double pi = 2 * asin(1.0); /// Declaring value of pi
auto om=std::complex<double>(cos(2*pi/n),sin(2*pi/n)); ///Calculating value of omega
auto *po = new std::complex<double>[n / 2]; /// Coefficents of odd power
auto *pe= new std::complex<double>[n/2]; /// Coefficents of even power
uint64_t k1 = 0, k2 = 0;
for (uint64_t j = 0; j < n; j++) {
if (j % 2 == 0) {
pe[k1++] = p[j]; /// Assigning values of even coefficents
auto *po= new std::complex<double>[n/2]; ///Coeeficents of odd power
} else
po[k2++] = p[j]; /// Assigning value of odd coefficents
}
int k1=0,k2=0;
for(int j=0;j<n;j++)
{
if(j%2==0){
pe[k1++]=p[j]; ///Assigning values of even ceofficents
auto *ye = FastFourierTransform(pe, n / 2); /// Recursive Call
}
else po[k2++]=p[j]; ///Assigning value of odd coefficents
auto *yo = FastFourierTransform(po, n / 2); /// Recursive Call
auto *y = new std::complex<double>[n]; /// Final value representation list
}
for (uint64_t i = 0; i < n / 2; i++) {
y[i] = ye[i] + pow(om, i) * yo[i]; /// Updating the first n/2 elements
y[i + n / 2] =
ye[i] - pow(om, i) * yo[i]; /// Updating the last n/2 elements
}
delete[] ye; /// Deleting dynamic array ye
auto *ye=FastFourierTransform(pe,n/2); ///Recursive Call
auto *yo=FastFourierTransform(po,n/2); ///Recursive Call
auto *y=new std::complex<double>[n]; /// Final value representation list
k1=0,k2=0;
for(int i=0;i<n/2;i++)
{
y[i]=ye[k1]+pow(om,i)*yo[k2]; /// Updating the first n/2 elements
y[i+n/2]=ye[k1]-pow(om,i)*yo[k2];/// Updating the last n/2 elements
k1++;
k2++;
}
delete[] ye; /// Deleting dynamic array ye
delete[] yo; /// Deleting dynamic array yo
delete[] pe; /// Deleting dynamic array pe
delete[] po; /// Deleting dynamic array po
return y; /// Returns the list
return y;
}
} // namespace numerical_methods
}/// namespace numerical_methods
/**
* @brief Self-test implementations
@ -87,22 +99,15 @@ std::complex<double> *FastFourierTransform(std::complex<double> *p,
* in predicted and true value is less than 0.000000000001.
* @returns void
*/
static void test() {
static void test() {
/* descriptions of the following test */
auto *t1 = new std::complex<double>[2]; /// Test case 1
t1[0] = {1, 0};
t1[1] = {2, 0};
/// auto is used inplace of std::complex<double> to reduce complexity
auto *t2 = new std::complex<double>[4]; /// Test case 2
t2[0] = {1, 0};
t2[1] = {2, 0};
t2[2] = {3, 0};
t2[3] = {4, 0};
uint8_t n1 = sizeof(t1) / sizeof(std::complex<double>);
uint8_t n2 = sizeof(t2) / sizeof(std::complex<double>);
std::complex<double> t1[2]={1,2}; /// Test case 1
std::complex<double> t2[4]={1,2,3,4}; /// Test case 2
uint8_t n1 = 2;
uint8_t n2 = 4;
std::vector<std::complex<double>> r1 = {
{3, 0}, {-1, 0}}; /// True Answer for test case 1
@ -128,10 +133,7 @@ static void test() {
o2++;
}
delete[] o1; /// Deleting dynamic array o1
delete[] o2; /// Deleting dynamic array o2
delete[] t1; /// Deleting dynamic array t1
delete[] t2; /// Deleting dynamic array t2
}
/**
@ -141,7 +143,10 @@ static void test() {
* calls automated test function to test the working of fast fourier transform.
* @returns 0 on exit
*/
int main(int argc, char const *argv[]) {
test(); // run self-test implementations
return 0;
int main(int argc, char const *argv[])
{
test();/// run self-test implementations
return 0;
}