Diff: src/Cortex-M4-M3/StatisticsFunctions/arm_rms_f32.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Cortex-M4-M3/StatisticsFunctions/arm_rms_f32.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,114 @@
+/* ----------------------------------------------------------------------  
+* Copyright (C) 2010 ARM Limited. All rights reserved.  
+*  
+* $Date:        29. November 2010  
+* $Revision: 	V1.0.3  
+*  
+* Project: 	    CMSIS DSP Library  
+* Title:		arm_rms_f32.c  
+*  
+* Description:	Root mean square value of an array of F32 type  
+*  
+* Target Processor: Cortex-M4/Cortex-M3
+*  
+* Version 1.0.3 2010/11/29 
+*    Re-organized the CMSIS folders and updated documentation.  
+*   
+* Version 1.0.2 2010/11/11  
+*    Documentation updated.   
+*  
+* Version 1.0.1 2010/10/05   
+*    Production release and review comments incorporated.  
+*  
+* Version 1.0.0 2010/09/20   
+*    Production release and review comments incorporated.  
+* ---------------------------------------------------------------------------- */ 
+ 
+#include "arm_math.h" 
+ 
+/**  
+ * @ingroup groupStats  
+ */ 
+ 
+/**  
+ * @defgroup RMS Root mean square (RMS)  
+ *  
+ *   
+ * Calculates the Root Mean Sqaure of the elements in the input vector.  
+ * The underlying algorithm is used:  
+ *  
+ * <pre>  
+ * 	Result = sqrt(((pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] * pSrc[blockSize-1]) / blockSize));  
+ * </pre>  
+ * 
+ * There are separate functions for floating point, Q31, and Q15 data types.   
+ */ 
+ 
+/**  
+ * @addtogroup RMS  
+ * @{  
+ */ 
+ 
+ 
+/**  
+ * @brief Root Mean Square of the elements of a floating-point vector.  
+ * @param[in]       *pSrc points to the input vector  
+ * @param[in]       blockSize length of the input vector  
+ * @param[out]      *pResult rms value returned here  
+ * @return none.  
+ *  
+ */ 
+ 
+void arm_rms_f32( 
+  float32_t * pSrc, 
+  uint32_t blockSize, 
+  float32_t * pResult) 
+{ 
+  float32_t sum = 0.0f;                          /* Accumulator */ 
+  float32_t in;                                  /* Tempoprary variable to store input value */ 
+  uint32_t blkCnt;                               /* loop counter */ 
+ 
+  /* loop Unrolling */ 
+  blkCnt = blockSize >> 2u; 
+ 
+  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.  
+   ** a second loop below computes the remaining 1 to 3 samples. */ 
+  while(blkCnt > 0u) 
+  { 
+    /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ 
+    /* Compute sum of the squares and then store the result in a temporary variable, sum  */ 
+    in = *pSrc++; 
+    sum += in * in; 
+    in = *pSrc++; 
+    sum += in * in; 
+    in = *pSrc++; 
+    sum += in * in; 
+    in = *pSrc++; 
+    sum += in * in; 
+ 
+    /* Decrement the loop counter */ 
+    blkCnt--; 
+  } 
+ 
+  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.  
+   ** No loop unrolling is used. */ 
+  blkCnt = blockSize % 0x4u; 
+ 
+  while(blkCnt > 0u) 
+  { 
+    /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ 
+    /* Compute sum of the squares and then store the results in a temporary variable, sum  */ 
+    in = *pSrc++; 
+    sum += in * in; 
+ 
+    /* Decrement the loop counter */ 
+    blkCnt--; 
+  } 
+ 
+  /* Compute Rms and store the result in the destination */ 
+  arm_sqrt_f32(sum / (float32_t) blockSize, pResult); 
+} 
+ 
+/**  
+ * @} end of RMS group  
+ */