How to enable screw pitch error compensation function in linuxcnc?

I have a a request, now joint0, joint1, joint2 compensation density need to be be set separately. I try a method, but it doesn't work. How to enable  screw pitch error compensation function in linuxcnc? What files need to be added?
 i add  screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, and modify ini.  
my test:I tried these data as shwn figure, there is no one has a offset.

 I expect the G0 x70 can move to position 50mm and G0 x0 can move to position 10mm. 

First, I draw a line 0mm to 70mm  with a ruler. Second, i home x and open a laser on the machine and the light is on the 0mm position.  Third, send a command G0 x70. Four, watch the light position, and it is on the position 70mm.

I change the offset from 20 to 10000 in screwcomp0.data and  there is also no offset.
 
Tips, home x is OK. Linear units = mm. I think the unit of every value is mm  in screwcomp0.data.
  i add screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, and modify ini.  Config/Sim/ add :screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, its' content shown as figure  Config/Sim/Axis/ add :screwcomp0.dat, screwcomp1.dat, screwcomp2.dat  screwcomp0.dat content is../screwcomp0.dat  Ini add:"COMP_FILE = screwcomp0.datCOMP_FILE_TYPE = 1, "COMP_FILE = screwcomp1.datCOMP_FILE_TYPE = 1, "COMP_FILE = screwcomp2.datCOMP_FILE_TYPE = 1 [JOINT_0]TYPE = LINEARHOME = 0.000MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp0.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000FERROR = 0.050MIN_FERROR = 0.010MIN_LIMIT = -10.0MAX_LIMIT = 10.0HOME_OFFSET = 0.0HOME_SEARCH_VEL = 20.0HOME_LATCH_VEL = 20.0HOME_USE_INDEX = NOHOME_IGNORE_LIMITS = NOHOME_SEQUENCE = 1HOME_IS_SHARED = 1 [JOINT_1]TYPE = LINEARHOME = 0.000MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp1.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000FERROR = 0.050MIN_FERROR = 0.010MIN_LIMIT = -10.0MAX_LIMIT = 10.0HOME_OFFSET = 0.0HOME_SEARCH_VEL = 20.0HOME_LATCH_VEL = 20.0HOME_USE_INDEX = NOHOME_IGNORE_LIMITS = NOHOME_SEQUENCE = 1 [JOINT_2]TYPE = LINEARHOME = 0.0MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp2.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000MIN_LIMIT = -8.0

I added these content as below:

i add screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, and modify ini.

Config/Sim/ add :
screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, its' content shown as figure

Config/Sim/Axis/ add :
screwcomp0.dat, screwcomp1.dat, screwcomp2.dat

screwcomp0.dat content is
../screwcomp0.dat


Ini add:
"COMP_FILE = screwcomp0.dat
COMP_FILE_TYPE = 1,

"COMP_FILE = screwcomp1.dat
COMP_FILE_TYPE = 1,

"COMP_FILE = screwcomp2.dat
COMP_FILE_TYPE = 1

[JOINT_0]
TYPE = LINEAR
HOME = 0.000
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp0.dat
COMP_FILE_TYPE = 1
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
FERROR = 0.050
MIN_FERROR = 0.010
MIN_LIMIT = -10.0
MAX_LIMIT = 10.0
HOME_OFFSET = 0.0
HOME_SEARCH_VEL = 20.0
HOME_LATCH_VEL = 20.0
HOME_USE_INDEX = NO
HOME_IGNORE_LIMITS = NO
HOME_SEQUENCE = 1
HOME_IS_SHARED = 1

[JOINT_1]
TYPE = LINEAR
HOME = 0.000
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp1.dat
COMP_FILE_TYPE = 1
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
FERROR = 0.050
MIN_FERROR = 0.010
MIN_LIMIT = -10.0
MAX_LIMIT = 10.0
HOME_OFFSET = 0.0
HOME_SEARCH_VEL = 20.0
HOME_LATCH_VEL = 20.0
HOME_USE_INDEX = NO
HOME_IGNORE_LIMITS = NO
HOME_SEQUENCE = 1

[JOINT_2]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 5
MAX_ACCELERATION = 50.0
COMP_FILE = screwcomp2.dat
COMP_FILE_TYPE = 1
INPUT_SCALE = 4000
OUTPUT_SCALE = 1.000
MIN_LIMIT = -8.0

I have a request, Now joint0, joint1, joint2 compensation density need to be be set separately. I try a method, but it doesn't work. How to enable  screw pitch error compensation function in linuxcnc?What files need to be added?
 I added these content as below:  i add screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, and modify ini.  Config/Sim/ add :screwcomp0.dat, screwcomp1.dat, screwcomp2.dat, its' content shown as figure  Config/Sim/screwcomp0.dat two lines content:0 10 -1070 20 -20 Config/Sim/Axis/ add :screwcomp0.dat, screwcomp1.dat, screwcomp2.dat  screwcomp0.dat content is../screwcomp0.dat  Ini add:"COMP_FILE = screwcomp0.datCOMP_FILE_TYPE = 1, "COMP_FILE = screwcomp1.datCOMP_FILE_TYPE = 1, "COMP_FILE = screwcomp2.datCOMP_FILE_TYPE = 1 [JOINT_0]TYPE = LINEARHOME = 0.000MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp0.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000FERROR = 0.050MIN_FERROR = 0.010MIN_LIMIT = -10.0MAX_LIMIT = 10.0HOME_OFFSET = 0.0HOME_SEARCH_VEL = 20.0HOME_LATCH_VEL = 20.0HOME_USE_INDEX = NOHOME_IGNORE_LIMITS = NOHOME_SEQUENCE = 1HOME_IS_SHARED = 1 [JOINT_1]TYPE = LINEARHOME = 0.000MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp1.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000FERROR = 0.050MIN_FERROR = 0.010MIN_LIMIT = -10.0MAX_LIMIT = 10.0HOME_OFFSET = 0.0HOME_SEARCH_VEL = 20.0HOME_LATCH_VEL = 20.0HOME_USE_INDEX = NOHOME_IGNORE_LIMITS = NOHOME_SEQUENCE = 1 [JOINT_2]TYPE = LINEARHOME = 0.0MAX_VELOCITY = 5MAX_ACCELERATION = 50.0COMP_FILE = screwcomp2.datCOMP_FILE_TYPE = 1INPUT_SCALE = 4000OUTPUT_SCALE = 1.000MIN_LIMIT = -8.0   my test:I tried these data as shwn figure, there is no one has a offset.  I expect the G0 x70 can move to position 50mm and G0 x0 can move to position 10mm.  First, I draw a line 0mm to 70mm with a ruler. Second, i home x and open a laser on the machine and the light is on the 0mm position. Third, send a command G0 x70. Four, watch the light position, and it is on the position 70mm. I change the offset from 20 to 10000 in screwcomp0.data and there is also no offset. Tips, home x is OK. Linear units = mm. I think the unit of every value is mm in screwcomp0.data.

i don't konw i can get answer from which category, so i put it in a few category.

Does anyone know about it?