Re: CSV Table reader

[Jorge Cardona]

I forgot about the file format, right now it only read files with two
columns, something like:

u0,y0
u1,y1
u2,y2
.
.
.
un,yn

2009/10/30 Jorge Cardona <jorgeecard...@gmail.com>:
> Hi, I made a little code that read a table in a csv format, and
> interpolate (linear) the data , and it can be used in models, i tried
> to use the CombiTable1D and CombiTableTime in Linux, and no one works
> for me, so, here is the Modelica code:
>
> model Table1D
>  Real y;
>  Real u;
>
>  parameter Real offset=0;
>  parameter String fileName; // Bug 1116
>
>  function initTable
>    input String filename;
>    input Real offset;
>    output Integer key;
>  external "C"
>      annotation(Library="table1d.o", Include="#include \"table1d.h\"");
>  end initTable;
>
>  function interpolateTable
>    input Integer key;
>    input Real u;
>    output Real y;
>  external "C"
>      annotation(Library="table1d.o", Include="#include \"table1d.h\"");
>  end interpolateTable;
>
> protected
>  Integer key;
>
> equation
>  when initial() then
>    key = initTable(fileName,offset);
>  end when;
>  y = interpolateTable(key, u);
> end Table1D;
>
> table1.h:
>
> #ifndef TABLE1D_H
> #define TABLE1D_H
> // Function that initiliaze the table lookup
> int initTable(const char* filename, const double offset);
>
> // Function that inerpolate the table lookup
> double interpolateTable(const int key, const double u);
>
> #endif
>
> table1.c:
>
> #include "table1d.h"
> #include <stdio.h>
> #include <stdlib.h>
> #include <sys/types.h>
> #include <sys/ipc.h>
> #include <sys/shm.h>
> #include <errno.h>
> #include <time.h>
>
> int initTable(const char* filename, const double offset)
> {
>  double u,y;
>  double **data = NULL;
>
>  // Open file
>  FILE* fd = fopen(filename,"r");
>
>  int n = 0;
>  while(fscanf(fd,"%lf,%lf",&u,&y)!=EOF){
>    data = (double**) realloc(data, (n+1)*sizeof(double*));
>    data[n] = (double*) calloc(2,sizeof(double));
>
>    data[n][0] = u - offset;
>    data[n][1] = y;
>
>    n++;
>  }
>
>  // Close file
>  close(fd);
>
>  srandom(time(NULL));
>
>  int key;
>  key = random();
>
>  int shmid;
>  shmid = shmget((key_t) key, sizeof(int) + 2 * n * sizeof(double),
> 0644 | IPC_CREAT | IPC_EXCL);
>
>  while((shmid < 0) && (errno == EEXIST)){
>    key = random();
>    shmid = shmget((key_t) key, sizeof(int) + 2 * n * sizeof(double),
> 0644 | IPC_CREAT | IPC_EXCL);
>  }
>
>  double *shdata;
>  int *shn;
>
>  shn = (int*) shmat(shmid, NULL, 0);
>  shn[0] = n;
>
>  shdata = (double*) (shn + 1);
>
>  int i;
>  for(i=0;i<n;i++){
>    shdata[2*i] = data[i][0];
>    shdata[2*i+1] = data[i][1];
>  }
>
>  shmdt(shn);
>  return key;
> }
>
> double interpolateTable(const int key, const double u)
> {
>  int i;
>
>  int shmid;
>  shmid = shmget((key_t) key, sizeof(int), 0666);
>  if(shmid < 0) exit(0);
>
>  int *shn;
>  shn = (int*) shmat(shmid, NULL, 0);
>  if(shn==(int*)-1) exit(0);
>
>  int n;
>  n = shn[0];
>
>  shmdt(shn);
>
>  shmid = shmget((key_t) key, sizeof(int) + 2*n*sizeof(double), 0666);
>  if(shmid < 0) exit(0);
>
>  shn = (int*) shmat(shmid, NULL, 0);
>  if(shn==(int*)-1) exit(0);
>
>  double *data;
>  data = (double*) (shn + 1);
>
>  double val;
>
>  if(n==1){
>    //  Constant function
>    val = data[1];
>  }
>  else if(u<=data[0]){
>    // u is less than min{u}
>    val = (data[3]-data[1])/(data[2]-data[0])*u + (data[1]*data[2] -
> data[0]*data[3])/(data[2]-data[0]) ;
>
>  }else if(u > data[2*n-2]){
>    // us is grater than max{u}
>    val = ((data[2*n-1]-data[2*n-3])/(data[2*n-2]-data[2*n-4]))*u +
> (data[2*n-3]*data[2*n-2] -
> data[2*n-4]*data[2*n-1])/(data[2*n-2]-data[2*n-4]);
>
>  } else {
>
>    for(i=0;i<n-1;i++){
>      if(u<data[2*i+2]){
>        val = ((data[2*i+3]-data[2*i+1])/(data[2*i+2]-data[2*i]))*u +
> (data[2*i+1]*data[2*i+2] -
> data[2*i]*data[2*i+3])/(data[2*i+2]-data[2*i]);
>        break;
>      }
>    }
>
>  }
>
>  shmdt(shn);
>  return val;
> }
>
> As you can see i use shared memory to share the data that is read in
> the initTable function, and the ask for it, it use a lot the system,
> and the system cpu usage increase a lot on the simulation, but it work
> pretty good, if you have a good idea to enhance this, please let me
> know.
>
> Bye.
>
> --
> Jorge Eduardo Cardona
> jorgeecard...@gmail.com
> jorgeecardona.blogspot.com
> ------------------------------------------------
> Linux registered user  #391186
> Registered machine    #291871
> ------------------------------------------------
>



-- 
Jorge Eduardo Cardona
jorgeecard...@gmail.com
jorgeecardona.blogspot.com
------------------------------------------------
Linux registered user  #391186
Registered machine    #291871
------------------------------------------------