Hi,
I have a table where one column consists of strings with point coordinates. I would like to evaluate the content of this point list for queries. To do this, i wanted to use a custom function that splits the string, performs queries (here: is the origin present in the point list) and returns a scalar.
Therefore i am expanding a dummy table with the string content:
let primitives=datatable(name:string, point_string:string)
[
"prim0", "[[0 0],[1 1],[2 0]]",
"prim1", "[[1 0],[1 1],[2 2],[3 3]]"
];
let unwrap= (array:string) { substring(array,1, string_size(array)-2)
};
let count_points_with_xy_zero = (point_string:string) {
toscalar( datatable(dummy:int)[1]
| extend points=split( unwrap(point_string),",")
| mv-expand points
| extend px = todecimal(split(unwrap(points)," ")[0])
| extend py = todecimal(split(unwrap(points)," ")[1])
| where px == 0 and py == 0
| count)
};
primitives
| where count_points_with_xy_zero(point_string) > 0
Unfortunately, i get an error: " Semantic error: Unresolved reference binding: 'point_string'".
The custom function works, if i pass a string directly, e.g.:
| where count_points_with_xy_zero("[[0 0],[1 1],[2 0]]") > 0
I re-wrote the query with an inline expansion which works as well:
let primitives=datatable(name:string, point_string:string)
[
"prim0", "[[0 0],[1 1],[2 0]]",
"prim1", "[[1 0],[1 1],[2 2],[3 3]]"
];
let unwrap= (array:string) { substring(array,1, string_size(array)-2)
};
primitives
| extend points=split( unwrap(point_string),",")
| mv-expand points
| extend px = todecimal(split(unwrap(points)," ")[0])
| extend py = todecimal(split(unwrap(points)," ")[1])
| where px == 0 and py == 0
| project-away points, px, py
| summarize take_any(*) by name
Is there a way to implement the desired functionality in a custom function or is this outside the specification of a custom function?
Thanks in advance,
Henning
