/* compute z(t) and t(z) from input t(z) */
void in_tz(int nt, float dt, float ft, int nz, float dz, float fz,
float tzin[], float zt[], float tz[])
{
int iz;
float vfz,vlz;
for (iz=0; iz<nz; iz++)
tz[iz] = tzin[iz];
vfz = 2.0*dz/(tz[1]-tz[0]);
vlz = 2.0*dz/(tz[nz-1]-tz[nz-2]);
tzzt(nz,dz,fz,tz,vfz,vlz,nt,dt,ft,zt);
}
/* compute z(t) and t(z) from input vint(z) */
void in_vintz(int nt, float dt, float ft, int nz, float dz, float fz,
float vintz[], float zt[], float tz[])
{
int iz;
float vfz,vlz;
tz[0] = 2.0*fz/vintz[0];
for (iz=1; iz<nz; iz++)
tz[iz] = tz[iz-1]+2.0*dz/vintz[iz-1];
vfz = vintz[0];
vlz = vintz[nz-1];
tzzt(nz,dz,fz,tz,vfz,vlz,nt,dt,ft,zt);
}
static void makezt (int nz, float dz, float fz, float v[],
int nt, float dt, float ft, float z[])
/************************************************************************
makezt - compute z(t) from v(z)
*************************************************************************
Input:
nz number of z values (output)
dz depth sampling interval (output)
fz first depth value (output)
v[] array of velocities as a function of time t
nt number of time samples
dt time sampling interval
ft first time sample
Output:
z[] array of z values as a function of t
*************************************************************************
Author: CWP: based on maketz by Dave Hale (c. 1992)
*************************************************************************/
{
int iz; /* counter */
float vfz; /* velocity at the first depth sample */
float vlz; /* velocity at the last depth sample */
float *t=NULL; /* array of time values as a function of z */
/* allocate space */
t = ealloc1float(nz);
/* calculate t(z) from v(z) */
t[0] = 2.0*fz/v[0];
for (iz=1; iz<nz; ++iz)
t[iz] = t[iz-1]+2.0*dz/v[iz-1];
vfz = v[0];
vlz = v[nz-1];
/* compute z(t) from t(z) */
tzzt(nz,dz,fz,t,vfz,vlz,nt,dt,ft,z);
free1float(t);
}
