Subsections
Time delay
Linear
| Set delay parameters |
|
| Delay |
1 |
| initial input |
0 |
| Buffer size |
1024 |
- Delay:The amount of simulation time that the input signal is
delayed before being propagated to the output. The value must be
nonnegative.
- initial input: The output generated by the block between the
start of the simulation and the Time delay.
- Buffer size:The initial memory allocation for the number of
points to store.
- always active: no
- direct-feedthrough: no
- zero-crossing: no
- mode: no
- number/sizes of inputs: 1 / -1
- number/sizes of outputs: 1 / -1
- number/sizes of activation inputs: 0 /
- number/sizes of activation outputs: 0 /
- continuous-time state: no
- discrete-time state: no
- name of computational function: time_delay
scilab/macros/scicos_blocks/linear/TIME_DELAY.sci
#include "scicos_block.h"
#include <math.h>
#include "../machine.h"
#if WIN32
#define NULL 0
#endif
extern void sciprint __PARAMS((char *fmt,...));
void time_delay(scicos_block *block,int flag)
{/* rpar[0]=delay, rpar[1]=init value, ipar[0]=buffer length */
double* pw,del,t,td;
int* iw;
int i,j,k;
if (flag == 4){/* the workspace is used to store previous values */
if ((*block->work=
scicos_malloc(sizeof(int)+sizeof(double)*
block->ipar[0]*(1+block->insz[0])))== NULL ) {
set_block_error(-16);
return;
}
pw=*block->work;
pw[0]=-block->rpar[0]*block->ipar[0];
for(i=1;i< block->ipar[0];i++){
pw[i]=pw[i-1]+block->rpar[0];
for(j=1;j< block->insz[0]+1;j++){
pw[i+block->ipar[0]*j]=block->rpar[1];
}
}
iw=(int *)(pw+block->ipar[0]*(1+block->insz[0]));
*iw=0;
}else if (flag == 5){
scicos_free(*block->work);
} else if (flag==0||flag==2) {
if (flag==2) do_cold_restart();
pw=*block->work;
iw=(int *)(pw+block->ipar[0]*(1+block->insz[0]));
t=get_scicos_time();
td=t-block->rpar[0];
if(td<pw[*iw]){
sciprint("delayed time=%f but last stored time=%f \r\n", td, pw[*iw]);
sciprint("Conisder increasing the length of buffer in delay block \r\n");
}
if (t>pw[(block->ipar[0]+*iw-1)%block->ipar[0]]){
for(j=1;j< block->insz[0]+1;j++){
pw[*iw +block->ipar[0]*j]=block->inptr[0][j-1];
}
pw[*iw]=t;
/*sciprint("**time is %f. I put %f, in %d \r\n", t,block->inptr[0][0],*iw);*/
*iw=(*iw+1)%block->ipar[0];
}else{
for(j=1;j< block->insz[0]+1;j++){
pw[(block->ipar[0]+*iw-1)%block->ipar[0] +block->ipar[0]*j]=block->inptr[0][j-1];
}
pw[(block->ipar[0]+*iw-1)%block->ipar[0]]=t;
/*sciprint("**time is %f. I put %f, in %d \r\n", t,block->inptr[0][0],*iw);*/
}
} else if (flag==1) {
pw=*block->work;
iw=(int *) (pw+block->ipar[0]*(1+block->insz[0]));
t=get_scicos_time();
td=t-block->rpar[0];
i=0;j= block->ipar[0]-1;
while (j-i>1) {
k=(i+j)/2;
if (td<pw[(k+*iw)%block->ipar[0]]) {
j=k;
}else if (td>pw[(k+*iw)%block->ipar[0]]) {
i=k;
}else{
i=k;
j=k;
break;
}
}
i=(i+*iw)%block->ipar[0];
j=(j+*iw)%block->ipar[0];
del=pw[j]-pw[i];
/*sciprint("time is %f. interpolating %d and %d, i.e. %f, %f\r\n", t,i,j,pw[i],pw[j]);*/
if(del!=0.0){
for (k=1;k<block->insz[0]+1;k++){
block->outptr[0][k-1]=((pw[j]-td)*pw[i+block->ipar[0]*k] +
(td-pw[i])*pw[j+block->ipar[0]*k])/del;
}
}else{
for (k=1;k<block->insz[0]+1;k++){
block->outptr[0][k-1]=pw[i+block->ipar[0]*k];
}
}
}
}
Ramine Nikoukhah
2004-06-22