# No method matching iterate(::Shapefile.Polygon)

**URL:** <https://discourse.julialang.org/t/no-method-matching-iterate-shapefile-polygon/118959>\
**Category:** Data\
**Tags:** question\
**Created:** [September 2, 2024, 7:50pm UTC](https://discourse.julialang.org/t/no-method-matching-iterate-shapefile-polygon/118959 "2024-09-02T19:50:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![schwob](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/schwob/32/49423_2.png) [@schwob](https://discourse.julialang.org/u/schwob)\
**Post date:** [September 2, 2024, 7:50pm UTC](https://discourse.julialang.org/t/no-method-matching-iterate-shapefile-polygon/118959/1 "2024-09-02T19:50:27Z")

</div>

I want to know if a lat/long coordinate is inside a specified set of US states. I downloaded a [shapefile](https://www2.census.gov/geo/tiger/GENZ2018/shp/cb_2018_us_state_500k.zip) for the US states from the [Census Bureau](https://www.census.gov/geographies/mapping-files/time-series/geo/carto-boundary-file.html). Suppose my coordinate is (38.4511,-80.5194), and I want to know if this coordinate is in the states of PA, NY, or NJ.

My current code is the following:

```julia
using Shapefile, GeoInterface, GeometryBasics
state_table = Shapefile.Table("path/to/cb_2018_us_state_500k/cb_2018_us_state_500k.shp")

## data frame for selecting states
state_DF = DataFrame(state_table)
keep_states = ["NJ", "PA", "NY"]
state_DF = filter(:STUSPS => x -> x in keep_states, state_DF)

function is_in(point::GeometryBasics.Point, polygon)
    return in(point, polygon) 
end

for i in 1:3
    if is_in(Point(-80.5194, 38.4511), state_DF[i,1])
        println("The point is inside ", state.attributes["STATE_NAME"]) 
        break # Stop after finding the first matching state
    end
end

```

Then, I get the following error:

```julia
ERROR: MethodError: no method matching iterate(::Shapefile.Polygon)
Closest candidates are:
  iterate(::Union{LinRange, StepRangeLen}) at range.jl:872
  iterate(::Union{LinRange, StepRangeLen}, ::Integer) at range.jl:872
  iterate(::T) where T<:Union{Base.KeySet{<:Any, <:Dict}, Base.ValueIterator{<:Dict}} at dict.jl:712
  ...

```

How can I accomplish my task? I’ve tried bypassing this error for a bit now.