Building Polygon yields a nil result about rgeo HOT 13 CLOSED

@handlers I got confused, sorry. I meant to point out that if you make a linear_ring first (linear_ring = factory.linear_ring(<array of points>)) and then pass that linear_ring to the polygon factory, it will return a polygon (factory.polygon(linear_ring)). Definitely a work around, but it works. I think you can even create the linear_ring from the line_string (factory.linear_ring(line_string)), but I'll have to double check that in the morning.

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+1 depending on the precision of the provided points, factory.polygon() returns nil
for spherical_factory SRID 4326

This has been open for a long time - Is there any update on when it's going to be fixed?
rgeo (0.3.20)

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Doesn't a polygon require at least 3 distinct points, otherwise it is just a 1-dimensional straight line? Try adding another point before the last, 'closing' point perhaps to make it into a polygon...

a=[factory.point(-92.272935049926986,15.831411705496032)]
 => [#<RGeo::Geographic::SphericalPointImpl:0x15b43d8 "POINT (-92.27293504992699 15.831411705496032)">] 

a << factory.point(-92.273079163754431,15.830847348631419)
 => [#<RGeo::Geographic::SphericalPointImpl:0x15b43d8 "POINT (-92.27293504992699 15.831411705496032)">, #<RGeo::Geographic::SphericalPointImpl:0x15cff98 "POINT (-92.27307916375443 15.83084734863142)">] 

# Add a NEW point
a << factory.point(-92.27315,15.83001)
 => [#<RGeo::Geographic::SphericalPointImpl:0x15b43d8 "POINT (-92.27293504992699 15.831411705496032)">, #<RGeo::Geographic::SphericalPointImpl:0x15cff98 "POINT (-92.27307916375443 15.83084734863142)">, #<RGeo::Geographic::SphericalPointImpl:0x15e49c0 "POINT (-92.27315 15.83001)">] 

# closing point
a << factory.point(-92.272935049926986,15.831411705496032)
 => [#<RGeo::Geographic::SphericalPointImpl:0x15b43d8 "POINT (-92.27293504992699 15.831411705496032)">, #<RGeo::Geographic::SphericalPointImpl:0x15cff98 "POINT (-92.27307916375443 15.83084734863142)">, #<RGeo::Geographic::SphericalPointImpl:0x15e49c0 "POINT (-92.27315 15.83001)">, #<RGeo::Geographic::SphericalPointImpl:0x15eaec4 "POINT (-92.27293504992699 15.831411705496032)">] 

linear_ring = factory.linear_ring(a)
 => #<RGeo::Geographic::SphericalLinearRingImpl:0x15ec878 "LINESTRING (-92.27293504992699 15.831411705496032, -92.27307916375443 15.83084734863142, -92.27315 15.83001, -92.27293504992699 15.831411705496032)"> 

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Cartesian polygon still returns nil. Trying the code on http://blog.daniel-azuma.com/archives/88 results in any polygon being returned as nil.

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If I use a different factory (like the spherical factory), I can create a polygon with the line_string

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I am having the same issue while following the tutorial. My factory object is:

RGeo::Geos::CAPIFactory:0x3fc076578cb4 srid=0 bufres=1 flags=8

Creating a polygon from a linestring returned nil. There is a rescue nil statement in the capi_factory.rb polygon method, but I have no idea why it's being tripped.

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@handlers I was able to get things to work if I made a linear_ring first. Can you gist your code that isn't working?

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@workmaster2n sure thing: https://gist.github.com/handlers/5693967

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@workmaster2n cool -- passing in a linear ring solves the problem for me! I wasn't able to pass a linestring into linear_ring().

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@workmaster2n ya linear_ring solves the problem with charm. author should update the tutorial.

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I found a bug on my side which caused this - hopefully this helps other people:

I had four points which would not be in the right order -- if you connected them by a line, the lines would cross.

#polygon and #linestring just return nil in that case, without any error or explanation.

RGeo should throw an error with a sufficient explanation, or even have code to fix the order

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@tilo is there a way to sort those points?

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Closing this since the spherical factory now raises an error when an invalid linear ring is being initialized.

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