I am getting following errors in mex file

------------------------------------------------------------------------
          Access violation detected at Sun Mar 26 12:21:15 2017
------------------------------------------------------------------------

Configuration:
  Crash Decoding      : Disabled - No sandbox or build area path
  Crash Mode          : continue (default)
  Current Graphics Driver: Unknown hardware 
  Default Encoding    : windows-1252
  Deployed            : false
  Graphics card 1     : NVIDIA ( 0x10de ) NVIDIA Quadro K620  Version 9.18.13.4052
  Host Name           : C1058
  MATLAB Architecture : win64
  MATLAB Entitlement ID: 859636
  MATLAB Root         : C:\Program Files\MATLAB\R2016b
  MATLAB Version      : 9.1.0.441655 (R2016b)
  OpenGL              : hardware
  Operating System    : Microsoft Windows 7 Enterprise 
  Processor ID        : x86 Family 6 Model 60 Stepping 3, GenuineIntel
  Virtual Machine     : Java 1.7.0_60-b19 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
  Window System       : Version 6.1 (Build 7601: Service Pack 1)

Fault Count: 1

Abnormal termination:
Access violation

Register State (from fault):
  RAX = 0000000000000000  RBX = 00000000000006a0
  RCX = 0000000000000004  RDX = 0000000000000001
  RSP = 000000000402a460  RBP = 00000000000001d3
  RSI = 0000000000000004  RDI = 00000000000001d3

     R8 = 0000000000000001   R9 = 000000000000025a
    R10 = 0000000000000258  R11 = 00000001b7d753c0
    R12 = 0000000000000258  R13 = 0000000000000000
    R14 = 00000001b7d753c0  R15 = 00000000ff7592e0

    RIP = 00000000322013de  EFL = 00010202

     CS = 0033   FS = 0053   GS = 002b

Stack Trace (from fault):
[  0] 0x00000000322013de C:\Text_Detection_Recognition\Word-Spotting\Word-Spotting\util\bin\computeStats_c.mexw64+00005086 mexFunction+00000958
[  1] 0x00000000fc5fc5d1 C:\Program Files\MATLAB\R2016b\bin\win64\libmex.dll+00116177 mexRunMexFile+00000129
[  2] 0x00000000fc5fb2e2 C:\Program Files\MATLAB\R2016b\bin\win64\libmex.dll+00111330 mexFeature_mexver+00001794
[  3] 0x00000000fc5fa506 C:\Program Files\MATLAB\R2016b\bin\win64\libmex.dll+00107782 mexUnlock+00020182
[  4] 0x000000000c6a46de C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00018142 Mfh_file::dispatch_fh_impl+00000434
[  5] 0x000000000c6a44b6 C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00017590 Mfh_file::dispatch_fh+00000062
[  6] 0x000000000c6a5827 C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00022567 Mfunction_handle::dispatch+00001015
[  7] 0x000000000d6c8c29 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00887849 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00798773
[  8] 0x000000000d6c8707 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00886535 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00797459
[  9] 0x000000000d6c74b8 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00881848 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00792772
[ 10] 0x000000000d649eab C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00368299 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00279223
[ 11] 0x000000000d649740 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00366400 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00277324
[ 12] 0x000000000d6d1efe C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00925438 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00836362
[ 13] 0x000000000d6d195a C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00923994 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00834918
[ 14] 0x000000000d6d1979 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00924025 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00834949
[ 15] 0x000000000c6a46de C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00018142 Mfh_file::dispatch_fh_impl+00000434
[ 16] 0x000000000c6a44b6 C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00017590 Mfh_file::dispatch_fh+00000062
[ 17] 0x000000000c6a5827 C:\Program Files\MATLAB\R2016b\bin\win64\m_dispatcher.dll+00022567 Mfunction_handle::dispatch+00001015
[ 18] 0x000000000d6cbfbd C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00901053 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00811977
[ 19] 0x000000000d69fbc0 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00719808 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00630732
[ 20] 0x000000000d6d728f C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00946831 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00857755
[ 21] 0x000000000d6d7b75 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00949109 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00860033
[ 22] 0x000000000d6d9151 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00954705 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00865629
[ 23] 0x000000000d6d9c95 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00957589 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00868513
[ 24] 0x000000000d6d932f C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00955183 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00866107
[ 25] 0x000000000d6d940d C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00955405 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00866329
[ 26] 0x000000000d6c8041 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00884801 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00795725
[ 27] 0x000000000d649eab C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00368299 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00279223
[ 28] 0x000000000d649740 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00366400 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00277324
[ 29] 0x000000000d643f8f C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00343951 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00254875
[ 30] 0x000000000d643aa1 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00342689 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00253613
[ 31] 0x000000000d643991 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00342417 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00253341
[ 32] 0x000000000d7d03e9 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+01967081 boost::serialization::singleton<boost::archive::detail::oserializer<boost::archive::polymorphic_oarchive,foundation::msg_svc::eventmgr::BaseEvent> >::get_instance+00003353
[ 33] 0x000000000d7d0372 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+01966962 boost::serialization::singleton<boost::archive::detail::oserializer<boost::archive::polymorphic_oarchive,foundation::msg_svc::eventmgr::BaseEvent> >::get_instance+00003234
[ 34] 0x000000000d692a61 C:\Program Files\MATLAB\R2016b\bin\win64\m_lxe.dll+00666209 boost::serialization::singleton<boost::archive::detail::iserializer<boost::archive::binaryTerm_iarchive,ir::IrTree> >::get_instance+00577133
[ 35] 0x000000000c90b3bd C:\Program Files\MATLAB\R2016b\bin\win64\m_interpreter.dll+00504765 inEvalCmdWithLocalReturn+00000065
[ 36] 0x00000000fb608ced C:\Program Files\MATLAB\R2016b\bin\win64\libmwbridge.dll+00101613 mnGetPrompt+00012957
[ 37] 0x00000000fb609ba3 C:\Program Files\MATLAB\R2016b\bin\win64\libmwbridge.dll+00105379 mnParser+00001091
[ 38] 0x000000000d406841   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00223297 mcr::runtime::setInterpreterThreadToCurrent+00025585
[ 39] 0x000000000d4057d7   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00219095 mcr::runtime::setInterpreterThreadToCurrent+00021383
[ 40] 0x000000000d405853   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00219219 mcr::runtime::setInterpreterThreadToCurrent+00021507
[ 41] 0x000000000d406141   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00221505 mcr::runtime::setInterpreterThreadToCurrent+00023793
[ 42] 0x00000000fd01d347   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00578375 iqm::UserEvalPlugin::pre+00030679
[ 43] 0x00000000fd029e7c   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00630396 iqm::UserEvalPlugin::pre+00082700
[ 44] 0x00000000fd017480   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00554112 iqm::UserEvalPlugin::pre+00006416
[ 45] 0x00000000fd02c99a   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00641434 iqm::UserEvalPlugin::pre+00093738
[ 46] 0x00000000fcff9a37   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00432695 iqm::PackagedTaskPlugin::PackagedTaskPlugin+00000727
[ 47] 0x00000000fcffa08f   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00434319 iqm::PackagedTaskPlugin::execute+00000575
[ 48] 0x00000000fcff9aa9   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00432809 iqm::PackagedTaskPlugin::PackagedTaskPlugin+00000841
[ 49] 0x00000000fcff9f04   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00433924 iqm::PackagedTaskPlugin::execute+00000180
[ 50] 0x00000000fcfd42fa   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00279290 iqm::Iqm::setupIqmFcnPtrs+00071530
[ 51] 0x00000000fcfd41d3   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00278995 iqm::Iqm::setupIqmFcnPtrs+00071235
[ 52] 0x00000000fcfb9e5a   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00171610 iqm::Iqm::deliver+00003274
[ 53] 0x00000000fcfbad2f   C:\Program Files\MATLAB\R2016b\bin\win64\iqm.dll+00175407 iqm::Iqm::deliver+00007071
[ 54] 0x0000000004538173 C:\Program Files\MATLAB\R2016b\bin\win64\libmwservices.dll+01147251 services::system_events::PpeDispatchHook::dispatchOne+00019059
[ 55] 0x000000000453c3a3 C:\Program Files\MATLAB\R2016b\bin\win64\libmwservices.dll+01164195 sysq::addProcessPendingEventsUnitTestHook+00001923
[ 56] 0x000000000453c580 C:\Program Files\MATLAB\R2016b\bin\win64\libmwservices.dll+01164672 sysq::addProcessPendingEventsUnitTestHook+00002400
[ 57] 0x000000000453d685 C:\Program Files\MATLAB\R2016b\bin\win64\libmwservices.dll+01169029 sysq::getCondition+00002917
[ 58] 0x000000000453e4b2 C:\Program Files\MATLAB\R2016b\bin\win64\libmwservices.dll+01172658 svWS_ProcessPendingEvents+00000162
[ 59] 0x000000000d406b7d   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00224125 mcr::runtime::setInterpreterThreadToCurrent+00026413
[ 60] 0x000000000d40726a   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00225898 mcr::runtime::setInterpreterThreadToCurrent+00028186
[ 61] 0x000000000d3fe385   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00189317 mcr_process_events+00010293
[ 62] 0x000000000d4002d2   C:\Program Files\MATLAB\R2016b\bin\win64\mcr.dll+00197330 mcr_process_events+00018306
[ 63] 0x000000000c61bd0e C:\Program Files\MATLAB\R2016b\bin\win64\MVMLocal.dll+00245006 mvm_server::inproc::LocalFactory::terminate+00070846
[ 64] 0x00000000fa942cd9   C:\Program Files\MATLAB\R2016b\bin\win64\mvm.dll+01125593 mvm::detail::initLocalMvmHack+00000521
[ 65] 0x00000000fa9432a5   C:\Program Files\MATLAB\R2016b\bin\win64\mvm.dll+01127077 mvm::detail::SessionImpl::privateSession+00000373
[ 66] 0x00000000fa9434b1   C:\Program Files\MATLAB\R2016b\bin\win64\mvm.dll+01127601 mvm::detail::SessionImpl::privateSession+00000897
[ 67] 0x0000000140006fd5 C:\Program Files\MATLAB\R2016b\bin\win64\MATLAB.exe+00028629
[ 68] 0x0000000140007661 C:\Program Files\MATLAB\R2016b\bin\win64\MATLAB.exe+00030305
[ 69] 0x00000000771259cd C:\Windows\system32\kernel32.dll+00088525 BaseThreadInitThunk+00000013
[ 70] 0x000000007735a561 C:\Windows\SYSTEM32\ntdll.dll+00173409 RtlUserThreadStart+00000033

This error was detected while a MEX-file was running. If the MEX-file
is not an official MathWorks function, please examine its source code
for errors. Please consult the External Interfaces Guide for information
on debugging MEX-files.

If this problem is reproducible, please submit a Service Request via:
    http://www.mathworks.com/support/contact_us/

A technical support engineer might contact you with further information.

[Geoff Hayes]

Asghar - there is probably a bug in the MEX code. You will need to post or attach the code (to this question) and include the command line call to the function (so that we can see the inputs) which will greatly help in trying to solve this problem.

[Asghar Ali]

Thank you so much Geoff Hayes. Here is code attached.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xmmintrin.h>

#include <assert.h>
#include <math.h>
#include <time.h>
#include <mex.h>

int sort(const void *x, const void *y) {
    if (*(int*)x > *(int*)y) return 1;
    else if (*(int*)x < *(int*)y) return -1;
    else return 0;
}

void mexFunction (int nlhs, mxArray *plhs[], 
        int nrhs, const mxArray *prhs[]) {

      /* Input parameters */
      /* [0]: Similarity matrix
       * [1]: queriesClasses
       * [2]: datasetClasses
       * [3]: NRelevantsPerQuery, number of relevants for each query.
       * [4]: queriesIdx (can be -1s)
       */
      /* Output parameters */
      /* [0]: p@1 array
       * [1]: map array
       * [2]: idx of the best match for each query 
       */

      int Nqueries, Ndataset;

      int *queriesCls;
      int *datasetCls;
      int *NRelevantsPerQuery;
      int *queriesIdx;        
      float *S;    

      float *pP1;
      float *pMap;
      int *bestIdx;    

      int i;
      int j;
      int k;
      float s;
      float s2;
      int better;
      int equal;
      float prec_at_k;

      float bestS;
      int p1;

      int *rank;
      int Nrelevants;
      int qclass;

      //int mwSize;
      /* Read Data */
      S =  (float*)mxGetData(prhs[0]);
      Nqueries = (int) mxGetN(prhs[0]);
      Ndataset = (int) mxGetM(prhs[0]);
      queriesCls =  (int*)mxGetData(prhs[1]);    
      datasetCls =  (int*)mxGetData(prhs[2]);
      NRelevantsPerQuery = (int*)mxGetData(prhs[3]);
      queriesIdx =  (int*)mxGetData(prhs[4]);

      /* Prepare output */
      //buflen =mxMalloc((mwSize)Nqueries);
      //dims[0]=Nqueries;
      //dims[0] = mxGetN(prhs[0], dims, (mwSize)buflen);
      //mwSize dims[0]=(int) mxGetN(prhs[0]); 
      //dims[0] = Nqueries;
      //int* tt = mxMalloc(Nqueries);
      mwSize dims[1];

      //dims[0] = (int)malloc((Nqueries)*sizeof(int));
      //int* dims= new int[1];
      dims[0]= Nqueries;
      plhs[0] = mxCreateNumericArray(1, dims, mxSINGLE_CLASS, mxREAL);
      plhs[1] = mxCreateNumericArray(1, dims, mxSINGLE_CLASS, mxREAL);
      plhs[2] = mxCreateNumericArray(1, dims, mxINT32_CLASS, mxREAL);
      pP1 = (float*)mxGetData(plhs[0]);
      pMap = (float*)mxGetData(plhs[1]);
      bestIdx = (int*)mxGetData(plhs[2]);

      /* one query per row, scores in each column */
      /* for each query */
      #pragma omp parallel  for
      for (i=0; i < Nqueries; i++)
      {
          pMap[i]=0;
          pP1[i]=0;
          /* Create a private list of relevants. */
           *rank = (int)malloc(NRelevantsPerQuery[i]*sizeof(int));
           Nrelevants = 0;
          /* Get its class */
           qclass = queriesCls[i];
          /* For each element in the dataset */
          bestS=-99999;
          p1=0;
          for (j=0; j < Ndataset; j++)
          {            
               s = S[i*Ndataset + j];
              /* Precision at 1 part */
              if (queriesIdx[i]!=j && s > bestS)
              {
                  bestS = s;
                  p1 = datasetCls[j]==qclass;
                  bestIdx[i] = j+1; /* Matlab style */
              }
              /* If it is from the same class and it is not the query idx, it is a relevant one. */
              /* Compute how many on the dataset get a better score and how many get an equal one, excluding itself and the query.*/
              if (datasetCls[j]==qclass && queriesIdx[i]!=j)
              {
                   better=0;
                   equal = 0;

                  for (k=0; k < Ndataset; k++)
                  {
                      if (k!=j && queriesIdx[i]!=k)
                      {
                           s2 = S[i*Ndataset + k];
                          if (s2> s) better++;
                          else if (s2==s) equal++;
                      }
                  }

                  rank[Nrelevants]=better+floor(equal/2.0);
                  Nrelevants++;
              }
          }
          /* Sort the ranked positions) */
          qsort(rank, Nrelevants, sizeof(int), sort);

          pP1[i] = p1;

          /* Get mAP and store it */
          for(j=0;j<Nrelevants;j++){
              /* if rank[i] >=k it was not on the topk. Since they are sorted, that means bail out already */

               prec_at_k =  ((float)(j+1))/(rank[j]+1);
              //mexPrintf("prec_at_k: %f\n", prec_at_k);
              pMap[i] += prec_at_k;            
          }
          pMap[i]/=Nrelevants;
      }
       return;

}

[Asghar Ali]

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xmmintrin.h>

#include <assert.h>
#include <math.h>
#include <time.h>
#include <mex.h>

int sort(const void *x, const void *y) {
    if (*(int*)x > *(int*)y) return 1;
    else if (*(int*)x < *(int*)y) return -1;
    else return 0;
}

void mexFunction (int nlhs, mxArray *plhs[], 
        int nrhs, const mxArray *prhs[]) {

      /* Input parameters */
      /* [0]: Similarity matrix
       * [1]: queriesClasses
       * [2]: datasetClasses
       * [3]: NRelevantsPerQuery, number of relevants for each query.
       * [4]: queriesIdx (can be -1s)
       */
      /* Output parameters */
      /* [0]: p@1 array
       * [1]: map array
       * [2]: idx of the best match for each query 
       */

      int Nqueries, Ndataset;

      int *queriesCls;
      int *datasetCls;
      int *NRelevantsPerQuery;
      int *queriesIdx;        
      float *S;    

      float *pP1;
      float *pMap;
      int *bestIdx;    

      int i;
      int j;
      int k;
      float s;
      float s2;
      int better;
      int equal;
      float prec_at_k;

      float bestS;
      int p1;

      int *rank;
      int Nrelevants;
      int qclass;

      //int mwSize;
      /* Read Data */
      S =  (float*)mxGetData(prhs[0]);
      Nqueries = (int) mxGetN(prhs[0]);
      Ndataset = (int) mxGetM(prhs[0]);
      queriesCls =  (int*)mxGetData(prhs[1]);    
      datasetCls =  (int*)mxGetData(prhs[2]);
      NRelevantsPerQuery = (int*)mxGetData(prhs[3]);
      queriesIdx =  (int*)mxGetData(prhs[4]);

      /* Prepare output */
      //buflen =mxMalloc((mwSize)Nqueries);
      //dims[0]=Nqueries;
      //dims[0] = mxGetN(prhs[0], dims, (mwSize)buflen);
      //mwSize dims[0]=(int) mxGetN(prhs[0]); 
      //dims[0] = Nqueries;
      //int* tt = mxMalloc(Nqueries);
      mwSize dims[1];

      //dims[0] = (int)malloc((Nqueries)*sizeof(int));
      //int* dims= new int[1];
      dims[0]= Nqueries;
      plhs[0] = mxCreateNumericArray(1, dims, mxSINGLE_CLASS, mxREAL);
      plhs[1] = mxCreateNumericArray(1, dims, mxSINGLE_CLASS, mxREAL);
      plhs[2] = mxCreateNumericArray(1, dims, mxINT32_CLASS, mxREAL);
      pP1 = (float*)mxGetData(plhs[0]);
      pMap = (float*)mxGetData(plhs[1]);
      bestIdx = (int*)mxGetData(plhs[2]);

      /* one query per row, scores in each column */
      /* for each query */
      #pragma omp parallel  for
      for (i=0; i < Nqueries; i++)
      {
          pMap[i]=0;
          pP1[i]=0;
          /* Create a private list of relevants. */
           *rank = (int)malloc(NRelevantsPerQuery[i]*sizeof(int));
           Nrelevants = 0;
          /* Get its class */
           qclass = queriesCls[i];
          /* For each element in the dataset */
          bestS=-99999;
          p1=0;
          for (j=0; j < Ndataset; j++)
          {            
               s = S[i*Ndataset + j];
              /* Precision at 1 part */
              if (queriesIdx[i]!=j && s > bestS)
              {
                  bestS = s;
                  p1 = datasetCls[j]==qclass;
                  bestIdx[i] = j+1; /* Matlab style */
              }
              /* If it is from the same class and it is not the query idx, it is a relevant one. */
              /* Compute how many on the dataset get a better score and how many get an equal one, excluding itself and the query.*/
              if (datasetCls[j]==qclass && queriesIdx[i]!=j)
              {
                   better=0;
                   equal = 0;

                  for (k=0; k < Ndataset; k++)
                  {
                      if (k!=j && queriesIdx[i]!=k)
                      {
                           s2 = S[i*Ndataset + k];
                          if (s2> s) better++;
                          else if (s2==s) equal++;
                      }
                  }

                  rank[Nrelevants]=better+floor(equal/2.0);
                  Nrelevants++;
              }
          }
          /* Sort the ranked positions) */
          qsort(rank, Nrelevants, sizeof(int), sort);

          pP1[i] = p1;

          /* Get mAP and store it */
          for(j=0;j<Nrelevants;j++){
              /* if rank[i] >=k it was not on the topk. Since they are sorted, that means bail out already */

               prec_at_k =  ((float)(j+1))/(rank[j]+1);
              //mexPrintf("prec_at_k: %f\n", prec_at_k);
              pMap[i] += prec_at_k;            
          }
          pMap[i]/=Nrelevants;
      }
       return;

}

[Asghar Ali]

if doqbs==0
[p1, mAP,bestIdx] = computeStats_c(single(S'),int32(queriesClases), int32(allClasses), int32(NRelevantsPerQuery), int32(keepQueries'-1));
else
    v = ones(N)*-1;
[p1, mAP,bestIdx] = computeStats_c(single(S'),int32(queriesClases), int32(allClasses), int32(NRelevantsPerQuery), int32(v));
end

[Asghar Ali]

the value of

S = 200X600,

queriesClases = 1x200,

allClasses = 1x600,

NRelevantsPerQuery = 200x1,

keepQueries = 200x1

[Asghar Ali]

Dear Geoff Hayes, above is the call of mex file and values of variables. I have tried a lot but could not find any solution.

Answer 1

[Jan]

Command like this are very tricky:

queriesCls =  (int*)mxGetData(prhs[1]);

Are you sure that the compiler uses the wanted number of bits? Prefer int32_T according to the type of the Matlab variable provided as input. E.g.:

plhs[2] = mxCreateNumericArray(1, dims, mxINT32_CLASS, mxREAL);
bestIdx = (int32_T *) mxGetData(plhs[2]);

[EDITED] This line looks cruel:

int *rank;
*rank = (int) malloc(NRelevantsPerQuery[i] * sizeof(int));

This would look better:

rank = (int *) malloc(NRelevantsPerQuery[i] * sizeof(int));

But even with this, rank is allocated in each iteration, but never free'd. This will leak memory.

[Asghar Ali]

Thank you so much Jan Simon, it is still showing the same error.

[Jan]

What exactly does "still" mean? What did you change? All occurences of the tricky int?

See [EDITED]