From bdf01b5ffbdf0139ed4522a5de7b8fd82335e1ef Mon Sep 17 00:00:00 2001
From: Vincenzo Petrolo <vincenzo@kernel-space.org>
Date: Sun, 4 Jul 2021 12:39:16 +0200
Subject: [PATCH] fix : correct mapping for frequencies

Signed-off-by: Vincenzo Petrolo <vincenzo@kernel-space.org>
---
 Desktop_Interface/asyncdft.cpp  | 13 ++++++-------
 Desktop_Interface/asyncdft.h    |  4 ++--
 Desktop_Interface/isodriver.cpp |  4 ++--
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/Desktop_Interface/asyncdft.cpp b/Desktop_Interface/asyncdft.cpp
index 1617dfbb..f97ce44d 100644
--- a/Desktop_Interface/asyncdft.cpp
+++ b/Desktop_Interface/asyncdft.cpp
@@ -1,6 +1,7 @@
 #include "asyncdft.h"
 #include <iostream>
 #include <math.h>
+#include "isobuffer.h"
 #define DBG 0
 
 
@@ -15,7 +16,7 @@ AsyncDFT::AsyncDFT()
     /*Initializing time domain window to 0s*/
     /*FFTW3 inits*/
     fftw_init_threads();
-    fftw_plan_with_nthreads(omp_get_max_threads());
+    fftw_plan_with_nthreads(omp_get_max_threads() * 2);
 #if DBG
     std::cout << "Starting with " << omp_get_max_threads() << "threads" << std::endl;
 #endif
@@ -114,14 +115,12 @@ QVector<double> AsyncDFT::getPowerSpectrum(QVector<double> input)
     return amplitude;
 }
 
-QVector<double> AsyncDFT::getFrequenciyWindow()
+QVector<double> AsyncDFT::getFrequenciyWindow(int samplesPerSeconds)
 {
-    int max_freq = 62500;
-    double delta_freq = ((double) 350000)/ ((double) n_samples);
-    int tot = max_freq/delta_freq + 1;
-    QVector<double> f(tot);
+    double delta_freq = ((double)  samplesPerSeconds)/ ((double) n_samples);
+    QVector<double> f(n_samples/2 + 1);
 
-    for (int i = 0; i < tot; i++) {
+    for (int i = 0; i < n_samples/2 + 1; i++) {
         f[i] = i*delta_freq;
     }
 
diff --git a/Desktop_Interface/asyncdft.h b/Desktop_Interface/asyncdft.h
index bae58d03..70e4fd4f 100644
--- a/Desktop_Interface/asyncdft.h
+++ b/Desktop_Interface/asyncdft.h
@@ -13,11 +13,11 @@ class AsyncDFT
 public:
     AsyncDFT();
     ~AsyncDFT();
-    static const int n_samples = 350000;
+    static const int n_samples = 1<<17;
 
     /* Raise exception if not ready yet*/
     QVector<double> getPowerSpectrum(QVector<double> input);
-    QVector<double> getFrequenciyWindow();
+    QVector<double> getFrequenciyWindow(int samplesPerSeconds);
 
     /*Add a sample to the time domain samples*/
     void addSample(short sample);
diff --git a/Desktop_Interface/isodriver.cpp b/Desktop_Interface/isodriver.cpp
index 9f96b175..68c7b4b6 100644
--- a/Desktop_Interface/isodriver.cpp
+++ b/Desktop_Interface/isodriver.cpp
@@ -740,7 +740,7 @@ void isoDriver::frameActionGeneric(char CH1_mode, char CH2_mode)
         if (spectrum) { /*If frequency spectrum mode*/
             try {
                 QVector<double> amplitude = internalBuffer375_CH1->async_dft.getPowerSpectrum(converted_dt_samples);
-                QVector<double> f = internalBuffer375_CH1->async_dft.getFrequenciyWindow();
+                QVector<double> f = internalBuffer375_CH1->async_dft.getFrequenciyWindow(internalBuffer375_CH1->m_samplesPerSecond);
                 double maximum = internalBuffer375_CH1->async_dft.maximum;
                 axes->graph(0)->setData(f,amplitude);
 #if 0
@@ -749,7 +749,7 @@ void isoDriver::frameActionGeneric(char CH1_mode, char CH2_mode)
                     axes->graph(1)->setData(f,amplitude);
                 }
 #endif
-                axes->xAxis->setRange(f.length(), 0);
+                axes->xAxis->setRange(f.last(), f.front());
                 axes->yAxis->setRange(maximum,0);
             }  catch (std::exception) {
                 std::cout << "Cannot yet get correct value for DFT" << std::endl;