Added suggested SLM down sampling factor, improved quite a lot of documentation. Measurement object can now work with old, as well as new measurement files.

src/lasp/__init__.py

@@ -11,7 +11,7 @@ __version__ = lasp_cpp.__version__
 # from .lasp_imptube import *  # TwoMicImpedanceTube
 from .lasp_measurement import *  # Measurement, scaleBlockSens
 from .lasp_octavefilter import *
-# from .lasp_slm import *  # SLM, Dummy
+from .lasp_slm import *  # SLM, Dummy
 from .lasp_record import *  # RecordStatus, Recording
 from .lasp_daqconfigs import *
 # from .lasp_siggen import *  # SignalType, NoiseType, SiggenMessage, SiggenData, Siggen

src/lasp/device/lasp_daqconfig.h

@@ -200,6 +200,19 @@ public:
    * output.
    */
   double digitalHighPassCutOn = -1;
+
+  /**
+   * @brief Compare two channels to eachother. They are equal when the name,
+   * sensitivity and quantity are the same.
+   *
+   * @param other The DaqChannel to compare with
+   *
+   * @return true if equal
+   */
+  bool operator==(const DaqChannel& other) const {
+    return other.name == name && other.sensitivity == sensitivity && 
+      other.qty == qty;
+  }
 };
 
 /**

src/lasp/dsp/lasp_avpowerspectra.h

@@ -7,6 +7,10 @@
 #include <optional>
 
 /** \defgroup dsp Digital Signal Processing utilities
+ * These are classes and functions used for processing raw signal data, to
+ * obtain statistics.
+ *
+ *
  * @{
  */
 

src/lasp/dsp/lasp_biquadbank.h

@@ -2,7 +2,7 @@
 #include "lasp_filter.h"
 
 /**
- * \ingroup dsp
+ * \addtogroup dsp
  * @{
  */
 
@@ -53,7 +53,8 @@ public:
   /**
    * @brief Initialize biquadbank.
    *
-   * @param filters Filters for each filter in the bank
+   * @param filters Filters for each filter in the bank. First axis isis the
+   * coefficient index, second axis is the filter index.
    * @param gains Gain values. Given as pointer, if not given (nulltpr), gains
    * are initialized with unity gain.
    */

src/lasp/dsp/lasp_slm.cpp

@@ -9,7 +9,7 @@
 
 using std::cerr;
 using std::endl;
-using std::runtime_error;
+using rte = std::runtime_error;
 using std::unique_ptr;
 
 SLM::SLM(const d fs, const d Lref, const us downsampling_fac, const d tau,
@@ -40,13 +40,13 @@ SLM::SLM(const d fs, const d Lref, const us downsampling_fac, const d tau,
   getPool();
 
   if (Lref <= 0) {
-    throw runtime_error("Invalid reference level");
+    throw rte("Invalid reference level");
   }
   if (tau <= 0) {
-    throw runtime_error("Invalid time constant for Single pole lowpass filter");
+    throw rte("Invalid time constant for Single pole lowpass filter");
   }
   if (fs <= 0) {
-    throw runtime_error("Invalid sampling frequency");
+    throw rte("Invalid sampling frequency");
   }
 }
 SLM::~SLM() {}
@@ -66,6 +66,21 @@ std::vector<unique_ptr<Filter>> createBandPass(const dmat &coefs) {
   }
   return bf;
 }
+us SLM::suggestedDownSamplingFac(const d fs,const d tau) {
+  if(tau<0) throw rte("Invalid time weightin time constant");
+  if(fs<=0) throw rte("Invalid sampling frequency");
+  // A reasonable 'framerate' for the sound level meter, based on the
+  // filtering time constant.
+  if (tau > 0) {
+    d fs_slm = 10 / tau;
+    if(fs_slm < 30) {
+      fs_slm = 30;
+    }
+    return std::max((us) 1, static_cast<us>(fs / fs_slm));
+  } else {
+    return 1;
+  }
+}
 
 SLM SLM::fromBiquads(const d fs, const d Lref, const us downsampling_fac,
     const d tau, const vd &pre_filter_coefs,

src/lasp/dsp/lasp_slm.h

@@ -98,7 +98,8 @@ public:
    * @param downsampling_fac Every 1/downsampling_fac value is returned from
    * compute()
    * @param tau Time consant of level meter
-   * @param bandpass_coefs Biquad filter coeffiecients for bandpass filter
+   * @param bandpass_coefs Biquad filter coefficients for bandpass filter. First axis isis the coefficient index, second axis is the filter index.
+
    *
    * @return Sound Level Meter object
    */
@@ -149,6 +150,20 @@ public:
    */
   vd Lmax() const { return 10 * arma::log10(Pmax / Lrefsq); };
 
+  /**
+   * @brief Comput a 'suggested' downsampling factor, i.e. a lower frame rate
+   * at which sound level meter values are returned from the computation. This
+   * is possible since the signal power is low-pas filtered with a single pole
+   * low pass filter. It can remove computational burden, especially for
+   * plotting, to have a value > 10.
+   *
+   * @param fs Sampling frequency of signal [Hz]
+   * @param tw Time weighting of SLM low pass filter
+   *
+   * @return Suggested downsampling factor, no unit. [-]
+   */
+  static us suggestedDownSamplingFac(const d fs,const d tw);
+
 private:
   vd run_single(vd input, const us filter_no);
 };

src/lasp/filter/filterbank_design.py

@@ -460,7 +460,15 @@ class OctaveBankDesigner(FilterBankDesigner):
 
 class ThirdOctaveBankDesigner(FilterBankDesigner):
 
-    def __init__(self, fs):
+    def __init__(self, fs: float):
+        """
+        Initialize ThirdOctaveBankDesigner, a filter bank designer for
+        one-third octave bands
+
+        Args:
+            fs: Sampling frequency in [Hz]
+
+        """
         super().__init__(fs)
         self.xs = list(range(-16, 14))
         # Text corresponding to the nominal frequency

src/lasp/lasp_common.py

@@ -84,7 +84,6 @@ class Qty:
 
 
 
-
 @unique
 class SIQtys(Enum):
     N = Qty(name='Number',
@@ -113,26 +112,20 @@ class SIQtys(Enum):
             cpp_enum = DaqChannel.Qty.Voltage
            )
 
-    @staticmethod
-    def fillComboBox(cb):
-        """
-        Fill  to a combobox
-
-        Args:
-            cb: QComboBox to fill
-        """
-        cb.clear()
-        for ty in SIQtys:
-            cb.addItem(f'{ty.value.unit_name}')
-        cb.setCurrentIndex(0)
-
     @staticmethod
     def default():
         return SIQtys.N.value
 
     @staticmethod
-    def getCurrent(cb):
+    def fromCppEnum(enum):
-        return list(SIQtys)[cb.currentIndex()]
+        """
+        Convert enumeration index from - say - a measurement file back into
+        physical quantity information.
+        """
+        for qty in SIQtys:
+            if qty.value.cpp_enum.value == enum:
+                return qty.value
+        raise RuntimeError(f'Qty corresponding to enum {enum} not found')
 
 
 @dataclass

src/lasp/lasp_measurement.py

@@ -16,9 +16,13 @@ is assumed to be acoustic data.
 'sensitivity': (Optionally) the stored sensitivity of the record channels.
                This can be a single value, or a list of sensitivities for
                each channel. Both representations are allowed.
+
+For measurement files of LASP < v1.0
 'qtys' : (Optionally): list of quantities that is recorded for each channel',
 if this array is not found. Quantities are defaulted to 'Number / Full scale'
 
+For measurement files of LASP >= 1.0
+
 - Datasets:
 
 'audio': 3-dimensional array of blocks of audio data. The first axis is the
@@ -46,7 +50,7 @@ from .lasp_config import LASP_NUMPY_FLOAT_TYPE
 from scipy.io import wavfile
 import os, time, wave, logging
 from .lasp_common import SIQtys, Qty, getFreq
-from .lasp_cpp import Window, DaqChannel
+from .lasp_cpp import Window, DaqChannel, LASP_VERSION_MAJOR
 
 
 def getSampWidth(dtype):
@@ -208,6 +212,13 @@ class Measurement:
             self.N = (self.nblocks * self.blocksize)
             self.T = self.N / self.samplerate
 
+            try:
+                self.version_major = f.attrs['LASP_VERSION_MAJOR']
+                self.version_minor = f.attrs['LASP_VERSION_MINOR']
+            except KeyError:
+                self.version_major = 0
+                self.version_minor = 1
+
             # Due to a previous bug, the channel names were not stored
             # consistently, i.e. as 'channel_names' and later camelcase.
             try:
@@ -239,6 +250,7 @@ class Measurement:
 
             self._time = f.attrs['time']
 
+            self._qtys = None
             try:
                 qtys_json = f.attrs['qtys']
                 # Load quantity data
@@ -246,9 +258,20 @@ class Measurement:
             except KeyError:
                 # If quantity data is not available, this is an 'old'
                 # measurement file.
-                logging.debug(f'Physical quantity data not available in measurement file. Assuming {SIQtys.default}')
+                pass
-                self._qtys = [SIQtys.default() for i in range(self.nchannels)]
 
+            try:
+                qtys_enum_idx = f.attrs['qtys_enum_idx']
+                self._qtys = [SIQtys.fromCppEnum(idx) for idx in qtys_enum_idx]
+            except KeyError:
+                pass
+
+            if self._qtys is None:
+                self._qtys = [SIQtys.default() for i in range(self.nchannels)]
+                logging.debug(f'Physical quantity data not available in measurement file. Assuming {SIQtys.default}')
+
+            
+                logging.debug(f'Physical quantity data not available in measurement file. Assuming {SIQtys.default}')
     def setAttribute(self, atrname, value):
         """
         Set an attribute in the measurement file, and keep a local copy in
@@ -276,14 +299,15 @@ class Measurement:
 
     @property
     def channelConfig(self):
-        chcfg = [DaqChannel(channel_enabled=True,
+        chcfg = []
-                           channel_name=chname,
+        for chname, sens, qty in zip(self.channelNames, self.sensitivity,
-                           sensitivity=sens,)
+                                     self.qtys):
-                for chname, sens in zip(
+            ch = DaqChannel()
-                    self.channelNames,
+            ch.enabled = True
-                    self.sensitivity)]
+            ch.name = chname
-        for i, qty in enumerate(self.qtys):
+            ch.sensitivity = sens
-            chcfg[i].qty = qty
+            ch.qty = qty.cpp_enum
+            chcfg.append(ch)
         return chcfg
 
     @channelConfig.setter
@@ -292,9 +316,9 @@ class Measurement:
         sens = []
         qtys = []
         for ch in chcfg:
-            chname.append(ch.channel_name)
+            chname.append(ch.name)
             sens.append(ch.sensitivity)
-            qtys.append(ch.qty)
+            qtys.append(SIQtys.fromCppEnum(ch.qty))
 
         self.channelNames = chname
         self.sensitivity = sens

src/lasp/lasp_record.py

@@ -9,7 +9,8 @@ import os
 import time
 import h5py
 import numpy as np
-from .lasp_cpp import InDataHandler, StreamMgr
+from .lasp_cpp import (InDataHandler, StreamMgr, LASP_VERSION_MAJOR,
+LASP_VERSION_MINOR)
 from .lasp_atomic import Atomic
 
 
@@ -119,12 +120,16 @@ class Recording:
 
         f = self.f
 
+        f.attrs['LASP_VERSION_MAJOR'] = LASP_VERSION_MAJOR
+        f.attrs['LASP_VERSION_MINOR'] = LASP_VERSION_MINOR
+
         # Set the bunch of attributes
         f.attrs['samplerate'] = daq.samplerate()
         f.attrs['nchannels'] = daq.neninchannels()
         f.attrs['blocksize'] = blocksize 
         f.attrs['sensitivity'] = [ch.sensitivity for ch in in_ch]
         f.attrs['channelNames'] = [ch.name for ch in in_ch]
+        # f.attrs['
 
         # Add the start delay here, as firstFrames() is called right after the
         # constructor is called.

src/lasp/lasp_slm.py

@@ -4,7 +4,7 @@
 Sound level meter implementation
 @author: J.A. de Jong - ASCEE
 """
-from .lasp_cpp import SLM as cppSLM
+from .lasp_cpp import cppSLM
 import numpy as np
 from .lasp_common import (TimeWeighting, FreqWeighting, P_REF)
 from .filter import SPLFilterDesigner
@@ -33,8 +33,8 @@ class SLM:
     def __init__(self,
                  fs,
                  fbdesigner=None, 
-                 tw=TimeWeighting.fast,
+                 tw: TimeWeighting =TimeWeighting.fast,
-                 fw=FreqWeighting.A,
+                 fw: FreqWeighting =FreqWeighting.A,
                  xmin = None,
                  xmax = None,
                  include_overall=True,
@@ -50,7 +50,7 @@ class SLM:
             fs: Sampling frequency [Hz]
             tw: Time Weighting to apply
             fw: Frequency weighting to apply
-            xmin: Filter designator of lowest band
+            xmin: Filter designator of lowest band. 
             xmax: Filter designator of highest band
             include_overall: If true, a non-functioning filter is added which
             is used to compute the overall level.
@@ -96,36 +96,42 @@ class SLM:
             assert fbdesigner.fs == fs
             sos_firstx = fbdesigner.createSOSFilter(self.xs[0]).flatten()
             self.nom_txt.append(fbdesigner.nominal_txt(self.xs[0]))
-            sos = np.empty((nfilters, sos_firstx.size), dtype=float, order='C')
+            sos = np.empty((sos_firstx.size, nfilters), dtype=float, order='C')
-            sos[0, :] = sos_firstx
+            sos[:, 0] = sos_firstx
 
             for i, x in enumerate(self.xs[1:]):
-                sos[i+1, :] = fbdesigner.createSOSFilter(x).flatten()
+                sos[:, i+1] = fbdesigner.createSOSFilter(x).flatten()
                 self.nom_txt.append(fbdesigner.nominal_txt(x))
 
             if include_overall:
                 # Create a unit impulse response filter, every third index equals 
                 # 1, so b0 = 1 and a0 is 1 (by definition)
                 # a0 = 1, b0 = 1, rest is zero
-                sos[-1,:] = sos_overall
+                sos[:,-1] = sos_overall
                 self.nom_txt.append('overall')
 
         else:
             # No filterbank, means we do only compute the overall values. This
             # means that in case of include_overall, it creates two overall
             # channels. That would be confusing, so we do not allow it.
-            sos = sos_overall[np.newaxis,:]
+            sos = sos_overall[:,np.newaxis]
             self.nom_txt.append('overall')
 
-        self.slm = cppSLM(fs, prefilter, sos,
+        # Downsampling factor, determine from single pole low pass filter time
-                          fs, tw[0], level_ref_value)
+        # constant, such that aliasing is ~ allowed at 20 dB lower value
+        # and 
+        dsfac = cppSLM.suggestedDownSamplingFac(fs, tw[0])
 
-        dsfac = self.slm.downsampling_fac
+        if prefilter is not None:
-        if dsfac > 0:
+            self.slm = cppSLM.fromBiquads(fs, level_ref_value, dsfac,
-            # Not unfiltered data
+                                          tw[0],
-            self.fs_slm = fs / self.slm.downsampling_fac
+                                          prefilter, sos)
         else:
-            self.fs_slm = fs
+            self.slm = cppSLM.fromBiquads(fs, level_ref_value, dsfac,
+                                          tw[0],
+                                          sos)
+
+        self.fs_slm = fs / dsfac
 
         # Initialize counter to 0
         self.N = 0
@@ -189,7 +195,6 @@ class SLM:
         output['mid'] = self.fbdesigner.fm(list(self.xs))
         logging.debug(list(self.xs))
         logging.debug(output['mid'])
-        # Indiced at 0, as pyxSLM always returns 2D arrays.
 
         if self.include_overall and self.fbdesigner is not None:
             output['overall'] = dat[-1,0]

src/lasp/pybind11/lasp_daqconfig.cpp

@@ -69,6 +69,8 @@ void init_daqconfiguration(py::module &m) {
       .value("UserDefined", DaqChannel::Qty::UserDefined);
   daqchannel.def_readwrite("qty", &DaqChannel::qty);
 
+  daqchannel.def("__eq__", [](const DaqChannel& a, const DaqChannel& b) { return a==b;});
+
   /// DaqConfiguration
   daqconfig.def(py::init<>());
   daqconfig.def(py::init<const DeviceInfo &>());

src/lasp/pybind11/lasp_dsp_pybind.cpp

@@ -69,15 +69,16 @@ void init_dsp(py::module &m) {
   /// AvPowerSpectra 
   py::class_<AvPowerSpectra> aps(m, "AvPowerSpectra");
   aps.def(py::init<const us, const Window::WindowType, const d, const int>(),
-          py::arg("nfft"), py::arg("WindowType"), py::arg("overlap_percentage"),
+          py::arg("nfft") = 2048, py::arg("windowType") =Window::WindowType::Hann, py::arg("overlap_percentage") = 50.0,
-          py::arg("time_constant"));
+          py::arg("time_constant") = -1);
+
   aps.def("compute", [](AvPowerSpectra &aps, const dmat &timedata) {
     std::optional<arma::cx_cube> res = aps.compute(timedata);
       return res.value_or(arma::cx_cube(0,0,0));
     }
   );
 
-  py::class_<SLM> slm(m, "SLM");
+  py::class_<SLM> slm(m, "cppSLM");
 
   slm.def_static(
       "fromBiquads",
@@ -94,5 +95,6 @@ void init_dsp(py::module &m) {
   slm.def("Lpeak", &SLM::Lpeak);
   slm.def("Leq", &SLM::Leq);
   slm.def("Lmax", &SLM::Lmax);
+  slm.def_static("suggestedDownSamplingFac", &SLM::suggestedDownSamplingFac);
 }
 /** @} */

src/lasp/pybind11/lasp_streammgr.cpp

@@ -2,6 +2,7 @@
 #include <pybind11/numpy.h>
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
+#include <functional>
 #include <stdint.h>
 
 using std::cerr;
@@ -31,4 +32,11 @@ void init_streammgr(py::module &m) {
   smgr.def("isStreamRunningOK", &StreamMgr::isStreamRunningOK);
   smgr.def("isStreamRunning", &StreamMgr::isStreamRunning);
   smgr.def("getDaq", &StreamMgr::getDaq, py::return_value_policy::reference);
+  smgr.def("rescanDAQDevices", [](StreamMgr& smgr, bool background) {
+      // A pure C++ callback is the second argument to rescanDAQDevices, which
+      // cannot be wrapped to Pybind11. Only the one without callback is
+      // forwarded here to Python code.
+      smgr.rescanDAQDevices(background);
+      },
+      py::arg("background")=false);
 }

test/test_cppslm.py

@@ -1,6 +1,6 @@
 #!/usr/bin/python3
 import numpy as np
-from lasp import SLM
+from lasp import cppSLM
 from lasp.filter import SPLFilterDesigner
 import matplotlib.pyplot as plt
 
@@ -11,7 +11,7 @@ def test_cppslm1():
     fs = 48000
     omg = 2*np.pi*1000
     
-    slm = SLM.fromBiquads(fs, 2e-5, 1, 0.125, [1.,0,0,1,0,0])
+    slm = cppSLM.fromBiquads(fs, 2e-5, 1, 0.125, [1.,0,0,1,0,0])
     
     t = np.linspace(0, 10, 10*fs, endpoint=False)
 
@@ -40,7 +40,7 @@ def test_cppslm2():
     omg = 2*np.pi*1000
     
     filt = SPLFilterDesigner(fs).A_Sos_design()
-    slm = SLM.fromBiquads(fs, 2e-5, 0, 0.125, filt.flatten(), [1.,0,0,1,0,0])
+    slm = cppSLM.fromBiquads(fs, 2e-5, 0, 0.125, filt.flatten(), [1.,0,0,1,0,0])
     
     t = np.linspace(0, 10, 10*fs, endpoint=False)
     
@@ -60,16 +60,33 @@ def test_cppslm2():
     # (Fast, Slow etc)
     assert np.isclose(out[-1,0], level, atol=1e-2)
 
+def test_cppslm3():
+    fs = 48000
+    omg = 2*np.pi*1000
+    
+    filt = SPLFilterDesigner(fs).A_Sos_design()
+    slm = cppSLM.fromBiquads(fs, 2e-5, 0, 0.125, filt.flatten(), [1.,0,0,1,0,0])
+    t = np.linspace(0, 10, 10*fs, endpoint=False)
+    
+    in_ = 10*np.sin(omg*t) * np.sqrt(2)+np.random.randn()
+    # Compute overall RMS
+    rms = np.sqrt(np.sum(in_**2)/in_.size)
+    # Compute overall level
+    level = 20*np.log10(rms/2e-5)
+    
+    
+    # Output of SLM
+    out = slm.run(in_)
+    
+    Lpeak = 20*np.log10(np.max(np.abs(in_)/2e-5))
+    Lpeak
+    slm.Lpeak()
+    assert np.isclose(out[-1,0], slm.Leq()[0][0], atol=1e-2)
+    assert np.isclose(Lpeak, slm.Lpeak()[0][0], atol=1e0)
+
 
 
 if __name__ == '__main__':
     test_cppslm1()
     test_cppslm2()
-
+    test_cppslm3()
-    # plt.plot(t,out[:,0])    
-    # plt.close('all')
-    # from scipy.signal import sosfreqz
-    # omg, H = sosfreqz(filt)
-    # freq = omg / (2*np.pi)*fs
-    # plt.figure()
-    # plt.semilogx(freq[1:],20*np.log10(np.abs(H[1:])))