Exercise 1 Answer – First Script

#!/bin/sh

sudata=/hou/data/D_152_001/SU_Class/class_project/seismic

# use sugethw to get start, end, increment

sugethw < ${sudata}/tiger.cdp2499.su ep | more

Exercise 1 Answer – Second Script

#!/bin/sh

# existing ep range is 811 through 1051, incremented by 2

# number of ep values is (1051 - 811 + 2) / 2 = 121

# new ep range needs to be 1-121(1)

# to make increment half, we divide by 2

# what do we do to make 1st value = 2/2 = 1?

# subtract 809, then divide by 2

# in suchw self-doc, val(key1) = (a + b * val(key2) + c * val(key3)) / d

sudata=/hou/data/D_152_001/SU_Class/class_project/seismic

suchw < ${sudata}/tiger.cdp2499.su key1=ep key2=ep a=-809 d=2 > ${sudata}/tiger.renumber.su

Exercise 1 Answer – Single-Script Alternative

#!/bin/sh

sudata=/hou/data/D_152_001/SU_Class/class_project/seismic

# single step method without interaction

# get 1st ep number

x=`sugethw < ${sudata}/tiger.cdp2499.su ep output=geom | head -1`

# subtract 2

x=`echo ${x}-2|bc`

echo "Bias=$x"

suchw < ${sudata}/tiger.cdp2499.su key1=ep key2=ep a=-$x d=2 > ${sudata}/tiger.renumber.su