Add parameters for min, max, and number of freqs for spectrum

demos/sphere/demo_sphere_irreg_waves.cpp

@@ -118,6 +118,9 @@ int main(int argc, char* argv[]) {
     wave_inputs.ramp_duration_       = 60.0;
     wave_inputs.wave_height_         = 2.0;
     wave_inputs.wave_period_         = 12.0;
+    wave_inputs.frequency_min_       = 0.001;
+    wave_inputs.frequency_max_       = 1.0;
+    wave_inputs.nfrequencies_        = 1000;
 
     std::shared_ptr<IrregularWaves> my_hydro_inputs;  // declare outside the try-catch block
 
@@ -231,4 +234,4 @@ int main(int argc, char* argv[]) {
     }
 
     return 0;
-}
+}

demos/sphere/demo_sphere_irreg_waves_eta_import.cpp

@@ -120,6 +120,9 @@ int main(int argc, char* argv[]) {
     params.simulation_duration_ = simulationDuration;
     params.ramp_duration_       = 0.0;
     params.eta_file_path_       = (DATADIR / "sphere" / "eta" / "eta.txt").lexically_normal().generic_string();
+    params.frequency_min_       = 0.001;
+    params.frequency_max_       = 1.0;
+    params.nfrequencies_        = 1000;
 
     std::shared_ptr<IrregularWaves> my_hydro_inputs;  // declare outside the try-catch block
 

demos/sphere/sphere_irreg_waves.cpp

@@ -139,15 +139,18 @@ int main(int argc, char* argv[]) {
     spring_1->SetDampingCoefficient(damping_coef);
     system.AddLink(spring_1);
 
-    auto my_hydro_inputs = std::make_shared<IrregularWave>();
-    //my_hydro_inputs->mode                   = WaveMode::irregular;                     // uses regular wave mode
-    my_hydro_inputs->wave_height_            = 2.0;
-    my_hydro_inputs->wave_period_            = 12.0;
-    my_hydro_inputs->simulation_duration_    = simulationDuration;
-    my_hydro_inputs->simulation_dt_          = timestep;
-    my_hydro_inputs->ramp_duration_          = 60.0;
-    //my_hydro_inputs->ramp_duration = 0.0;
-    //my_hydro_inputs->SetSpectrumFrequencies(0.001, 1.0, 1000);
+    IrregularWaveParams wave_inputs;
+    wave_inputs.num_bodies_          = bodies.size();
+    wave_inputs.simulation_dt_       = timestep;
+    wave_inputs.simulation_duration_ = simulationDuration;
+    wave_inputs.ramp_duration_       = 60.0;
+    wave_inputs.wave_height_         = 2.0;
+    wave_inputs.wave_period_         = 12.0;
+    wave_inputs.frequency_min_       = 0.001;
+    wave_inputs.frequency_max_       = 1.0;
+    wave_inputs.nfrequencies_        = 1000;
+
+    auto my_hydro_inputs = std::make_shared<IrregularWave>(wave_inputs);
     //TODO add option for PiersonMoskowitzSpectrumHz or other spectrum, have a default, do PM for now
 
     std::vector<std::shared_ptr<ChBody>> bodies;

include/hydroc/wave_types.h

@@ -242,6 +242,9 @@ struct IrregularWaveParams {
     std::string eta_file_path_;
     double wave_height_             = 0.0;
     double wave_period_             = 0.0;
+    double frequency_min_           = 0.001;
+    double frequency_max_           = 1.0;
+    double nfrequencies_            = 0;
     double peak_enhancement_factor_ = 1.0;
     bool is_normalized_             = false;
     int seed_                       = 1;

src/wave_types.cpp

@@ -401,7 +401,16 @@ Eigen::VectorXd IrregularWaves::SetSpectrumFrequencies(double start, double end,
 
 void IrregularWaves::CreateSpectrum() {
     // Define the frequency vector
-    spectrum_frequencies_ = Eigen::VectorXd::LinSpaced(1000, 0.001, 1.0);
+    int nf;
+    if (params_.nfrequencies_ == 0) {
+        // automatically calculate number of frequencies necessary so that timeseries does not repeat itself
+        double df = 1.0 / params_.simulation_duration_;
+        nf = std::ceil((params_.frequency_max_-params_.frequency_min_) / df);
+
+    } else {
+        nf = params_.nfrequencies_;
+    }
+    spectrum_frequencies_ = Eigen::VectorXd::LinSpaced(nf, params_.frequency_min_, params_.frequency_max_);
 
     // Calculate the Pierson-Moskowitz Spectrum
     spectral_densities_ =