arm_hamming_distance.c 1.8 KB

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  1. /* ----------------------------------------------------------------------
  2. * Project: CMSIS DSP Library
  3. * Title: arm_hamming_distance.c
  4. * Description: Hamming distance between two vectors
  5. *
  6. *
  7. * Target Processor: Cortex-M cores
  8. * -------------------------------------------------------------------- */
  9. /*
  10. * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
  11. *
  12. * SPDX-License-Identifier: Apache-2.0
  13. *
  14. * Licensed under the Apache License, Version 2.0 (the License); you may
  15. * not use this file except in compliance with the License.
  16. * You may obtain a copy of the License at
  17. *
  18. * www.apache.org/licenses/LICENSE-2.0
  19. *
  20. * Unless required by applicable law or agreed to in writing, software
  21. * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  22. * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  23. * See the License for the specific language governing permissions and
  24. * limitations under the License.
  25. */
  26. #include "arm_math.h"
  27. #include <limits.h>
  28. #include <math.h>
  29. extern void arm_boolean_distance_TF_FT(const uint32_t *pA
  30. , const uint32_t *pB
  31. , uint32_t numberOfBools
  32. , uint32_t *cTF
  33. , uint32_t *cFT
  34. );
  35. /**
  36. @addtogroup BoolDist
  37. @{
  38. */
  39. /**
  40. * @brief Hamming distance between two vectors
  41. *
  42. * @param[in] pA First vector of packed booleans
  43. * @param[in] pB Second vector of packed booleans
  44. * @param[in] numberOfBools Number of booleans
  45. * @return distance
  46. *
  47. */
  48. float32_t arm_hamming_distance(const uint32_t *pA, const uint32_t *pB, uint32_t numberOfBools)
  49. {
  50. uint32_t ctf=0,cft=0;
  51. arm_boolean_distance_TF_FT(pA, pB, numberOfBools, &ctf, &cft);
  52. return(1.0*(ctf + cft) / numberOfBools);
  53. }
  54. /**
  55. * @} end of BoolDist group
  56. */