Netlogo-Why does storing data from turtles into the global variable matrix crash - netlogo

Question

My program has an array for each turtle, and when I want to store the data in this array to the global variable matrix, the program does not work properly
I want to be able to implement an array for each turtle that stores data into a global variable matrix................................................................................................
The problem arises in：
``
let n 0 while [n < 40][ let tmp_num1 (array:item get_k n) matrix:set col_k CatNum n tmp_num
Here is my full code
`extensions [
array
matrix]
globals[
i
v
col_k
]
breed[cats cat]
breed[rats rat]
cats-own [
CatNum
data_from_rat
a_array
GetRatNum
get_k
k ;;
]
rats-own[
kg
num
]
to setup
clear-all
reset-ticks
set i 0
set v 0
creat-animals
creat-world
set col_k matrix:make-constant 40 40 0
ask cats[
set k 0
set a_array array:from-list n-values 20 [0]
set get_k array:from-list n-values 20 [0]
]
end
to go
ask n-of 20 rats[ ;;
if i < 20 [
set num i
set i i + 1
]
]
ask rats[
update
creat-ratnum
fd 3
rt random 90
]
ask n-of 40 cats[
if v < 40 [
set CatNum v
set v v + 1
]
]
ask cats[
let agsets other turtles-here with [breed = rats]
if count agsets >= 1
[
interaction(one-of agsets)
]
fd 3
lt random 90
;;print_array
]
tick
end
to creat-animals
create-cats 40[
set shape "cat"
set size 2
set color orange
setxy random-xcor random-ycor
]
create-rats 20[
set shape "mouse side"
set size 2
set color pink
setxy random-xcor random-ycor
]
end
to creat-world
ask patches[
set pcolor white
]
end
to creat-ratnum
loop[
if i >= 20 [stop]
set num i
set i i + 1
]
end
to update
set kg random-float 1
end
to interaction[provider]
set data_from_rat([kg] of provider)
set GetRatNum ([num] of provider)
let tmp_num (array:item get_k GetRatNum) ;;
ifelse tmp_num >= 1 [
set tmp_num tmp_num + 1
array:set get_k GetRatNum tmp_num ;;
;print (word "this is:" tmp_num)
][
set tmp_num tmp_num + 1
array:set get_k GetRatNum tmp_num
]
array:set a_array GetRatNum data_from_rat ;;
;;
let n 0
while [n < 40][
let tmp_num1 (array:item get_k n)
matrix:set col_k CatNum n tmp_num
]
end`
``