Some cleaning : C code, some Python comment, picture placement.

Author: christophe0606

content/learning-paths/embedded-and-microcontrollers/cmsisdsp-dev-with-python/how-to-4.md

@@ -62,10 +62,9 @@ vad = np.array([[w]*(winLength-winOverlap) for w in cleaned]).flatten()
 ax.plot(data)
 ax.plot(vad)
 ```
-The reference implementation works. You can now implement the same version using CMSIS-DSP.
-
 ![vad alt-text#center](vad.png "Figure 3. VAD")
 
+The reference implementation works. You can now implement the same version using CMSIS-DSP.
 
 ### CMSIS-DSP Q15 VAD
 

content/learning-paths/embedded-and-microcontrollers/cmsisdsp-dev-with-python/how-to-5.md

@@ -134,8 +134,6 @@ The FFT length must be a power of 2. The slice length is not necessarily a power
 ```python
 class NoiseSuppressionReference(NoiseSuppression):
     def __init__(self,slices):
-        # In a better version this could be computed from the signal length by taking the
-        # smaller power of two greater than the signal length.
         NoiseSuppression.__init__(self,slices)
 
         # Compute the vad signal

content/learning-paths/embedded-and-microcontrollers/cmsisdsp-dev-with-python/how-to-7.md

@@ -29,8 +29,10 @@ def rescale(self,w):
 ```
 #### C Version
 
-
 ```C
+#include "dsp/basic_math_functions.h"
+#include "dsp/statistics_functions.h"
+
 arm_status rescale(q15_t *w, uint32_t nb,q15_t *the_max)
 {
     uint32_t index;
@@ -46,7 +48,7 @@ arm_status rescale(q15_t *w, uint32_t nb,q15_t *the_max)
        status = arm_divide_q15(0x7FFF,*the_max,&quotient,&the_shift);
        if (status == ARM_MATH_SUCCESS)
        {
-         arm_scale_q15(w,quotient,the_shift,w,nb);
+         arm_scale_q15(w,quotient,(int8_t)the_shift,w,nb);
        }
     }
 
@@ -82,20 +84,24 @@ def signal_energy_q15(window):
 
 #### C version
 ```C
-int16_t signal_energy_q15(q15_t *window,unit32_t nb)
+#include "dsp/basic_math_functions.h"
+#include "dsp/fast_math_functions.h"
+#include "dsp/statistics_functions.h"
+
+int16_t signal_energy_q15(q15_t *window,uint32_t nb)
 {
     q15_t mean,neg_mean;
     arm_mean_q15(window,nb,&mean);
 
-    arm_negate_q15(&mean,&mean,1);
+    arm_negate_q15(&mean,&neg_mean,1);
 
     arm_offset_q15(window,neg_mean,window,nb);
 
     q63_t energy_q63;
     q15_t energy;
     arm_power_q15(window,nb,&energy_q63);
 
-    energy=(q15_t)_SSAT((q31_t)(energy_q63>>20),16);
+    energy=(q15_t)__SSAT((q31_t)(energy_q63>>20),16);
 
     // Fixed point format of result is on 16 bit
     // but the specific format has not been identified
@@ -105,7 +111,7 @@ int16_t signal_energy_q15(q15_t *window,unit32_t nb)
 
     arm_vlog_q15(&energy,&dB,1);
 
-    return(dB)
+    return(dB);
 }
 ```