Improved Windows instructions (#116)

Signed-off-by: ahcorde <[email protected]>

Author: ahcorde

examples/imu_noise/README.md

@@ -12,22 +12,48 @@ To evaluate noise, first build and run.
 mkdir build
 cd build
 cmake ..
+```
+
+### Ubuntu Or MacOS
+
+```bash
 make
+```
+
+This will generate the `sensor_noise` executable under `build`.
+
+### Windows
+
+```bash
+cmake --build . --config Release
+```
+
+This will generate the `sensor_noise.exe` executable under `build\Release`.
+
+```
+# Ubuntu or MacOS
 ./sensor_noise
+
+# Windows
+.\Release\sensor_noise.exe
 ```
 
 This will generate two series of samples, one for accelerometer and another for gyroscope.
 
 To use the analysis script, first install Allan Tools:
 
 ```
-pip install --user allantools
+pip install --user allantools scipy
 ```
 
 Then execute the script:
 
 ```
+# Ubuntu o MacOS
 ../plot_samples.py
+
+# Windows
+python.exe ..\plot_samples.py
 ```
 
 This will produce two graphs: the Allan Deviation plots for both the simulated accelerometer and gyroscope.  The values on these graphs should correspond closely to the inputs:
@@ -39,11 +65,9 @@ This will produce two graphs: the Allan Deviation plots for both the simulated a
   * sigma_N: Accelerometer Noise Density
   * sigma_K: Accelerometer Random Walk
 
-
 While this technique is used here to validate the operation of the algorithm, it could also be used
 to estimate the noise parameters for a real IMU.
 
-
 ## References:
 
 * Python Allan Tools: https://github.com/aewallin/allantools

examples/imu_noise/main.cc

@@ -26,21 +26,21 @@
 
 static constexpr double kSampleFrequency = 100.0;
 // 16-bit ADC
-static constexpr double kSamplePrecision = 1.0/pow(2.0, 16.0);
+static double kSamplePrecision = 1.0/pow(2.0, 16.0);
 // Generate 6 hours of data.
 static constexpr double kNumSamples = 6 * 3600 * kSampleFrequency;
 
 // Default values for use with ADIS16448 IMU
 // These values come from the Rotors default values:
 // https://github.com/ethz-asl/rotors_simulator/blob/513bb92da0c1a0c968bdc679dffc8fe7d77de918/rotors_gazebo_plugins/include/rotors_gazebo_plugins/gazebo_imu_plugin.h#L40
 static constexpr double kDefaultAdisGyroscopeNoiseDensity =
-    2.0 * 35.0 / 3600.0 / 180.0 * M_PI;
+    2.0 * 35.0 / 3600.0 / 180.0 * IGN_PI;
 static constexpr double kDefaultAdisGyroscopeRandomWalk =
-    2.0 * 4.0 / 3600.0 / 180.0 * M_PI;
+    2.0 * 4.0 / 3600.0 / 180.0 * IGN_PI;
 static constexpr double kDefaultAdisGyroscopeBiasCorrelationTime =
     1.0e+3;
 static constexpr double kDefaultAdisGyroscopeTurnOnBiasSigma =
-    0.5 / 180.0 * M_PI;
+    0.5 / 180.0 * IGN_PI;
 static constexpr double kDefaultAdisAccelerometerNoiseDensity =
     2.0 * 2.0e-3;
 static constexpr double kDefaultAdisAccelerometerRandomWalk =