What is a non-concave and non-convex polygon called?












0












$begingroup$


I am writing a software function to plot the outer points of an n-sided polygon and I'm having trouble ensuring I use the correct terminology. The function I've written simply renders the calculated points of a predetermined polygon in two dimensional space. These polygons are neither convex nor concave and thus I believe the name I should give the function is Render Uniform Polygon; however, I believe uniform may not be the correct word and could end up in a debate over the name. The function itself performs three actions to achieve the goal:




  1. Calculate the angle of each point $theta_n$.

  2. Calculate the new position $P_n$.

  3. Render a 3px by 3px dot at the new position.


The math for calculating $theta_n$ is:



$$theta_n = frac{biggl(bigl(frac{360°}{p}bigr)n + phibiggr)pi}{180°}$$



Where:





  • $p$ is the number of points in the polygon.


  • $n$ is the current point.


  • $phi$ is the global rotation angle.


Once $theta_n$ has been calculated with the math above, I then use it to calculate the new position with the following:



$$P_{_n{x, y}} = C_{x, y} + (cos(theta_n), sin(theta_n))r$$



Where:





  • $P_n$ is current point's position.


  • $C_{x, y}$ is the center of the polygon.


  • $r$ is the radius of the polygon.


This method can be used to render any polygon with three sides or more, and since the radius is predefined there isn't a case where the polygon can be convex or concave.





What is a polygon that is neither convex nor concave called?










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$endgroup$








  • 1




    $begingroup$
    All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:22










  • $begingroup$
    @AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
    $endgroup$
    – PerpetualJ
    Jan 21 at 18:23








  • 1




    $begingroup$
    Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:25






  • 2




    $begingroup$
    For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
    $endgroup$
    – Ross Millikan
    Jan 21 at 18:25










  • $begingroup$
    @RossMillikan: Excellent point, I agree!
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:26
















0












$begingroup$


I am writing a software function to plot the outer points of an n-sided polygon and I'm having trouble ensuring I use the correct terminology. The function I've written simply renders the calculated points of a predetermined polygon in two dimensional space. These polygons are neither convex nor concave and thus I believe the name I should give the function is Render Uniform Polygon; however, I believe uniform may not be the correct word and could end up in a debate over the name. The function itself performs three actions to achieve the goal:




  1. Calculate the angle of each point $theta_n$.

  2. Calculate the new position $P_n$.

  3. Render a 3px by 3px dot at the new position.


The math for calculating $theta_n$ is:



$$theta_n = frac{biggl(bigl(frac{360°}{p}bigr)n + phibiggr)pi}{180°}$$



Where:





  • $p$ is the number of points in the polygon.


  • $n$ is the current point.


  • $phi$ is the global rotation angle.


Once $theta_n$ has been calculated with the math above, I then use it to calculate the new position with the following:



$$P_{_n{x, y}} = C_{x, y} + (cos(theta_n), sin(theta_n))r$$



Where:





  • $P_n$ is current point's position.


  • $C_{x, y}$ is the center of the polygon.


  • $r$ is the radius of the polygon.


This method can be used to render any polygon with three sides or more, and since the radius is predefined there isn't a case where the polygon can be convex or concave.





What is a polygon that is neither convex nor concave called?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:22










  • $begingroup$
    @AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
    $endgroup$
    – PerpetualJ
    Jan 21 at 18:23








  • 1




    $begingroup$
    Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:25






  • 2




    $begingroup$
    For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
    $endgroup$
    – Ross Millikan
    Jan 21 at 18:25










  • $begingroup$
    @RossMillikan: Excellent point, I agree!
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:26














0












0








0





$begingroup$


I am writing a software function to plot the outer points of an n-sided polygon and I'm having trouble ensuring I use the correct terminology. The function I've written simply renders the calculated points of a predetermined polygon in two dimensional space. These polygons are neither convex nor concave and thus I believe the name I should give the function is Render Uniform Polygon; however, I believe uniform may not be the correct word and could end up in a debate over the name. The function itself performs three actions to achieve the goal:




  1. Calculate the angle of each point $theta_n$.

  2. Calculate the new position $P_n$.

  3. Render a 3px by 3px dot at the new position.


The math for calculating $theta_n$ is:



$$theta_n = frac{biggl(bigl(frac{360°}{p}bigr)n + phibiggr)pi}{180°}$$



Where:





  • $p$ is the number of points in the polygon.


  • $n$ is the current point.


  • $phi$ is the global rotation angle.


Once $theta_n$ has been calculated with the math above, I then use it to calculate the new position with the following:



$$P_{_n{x, y}} = C_{x, y} + (cos(theta_n), sin(theta_n))r$$



Where:





  • $P_n$ is current point's position.


  • $C_{x, y}$ is the center of the polygon.


  • $r$ is the radius of the polygon.


This method can be used to render any polygon with three sides or more, and since the radius is predefined there isn't a case where the polygon can be convex or concave.





What is a polygon that is neither convex nor concave called?










share|cite|improve this question











$endgroup$




I am writing a software function to plot the outer points of an n-sided polygon and I'm having trouble ensuring I use the correct terminology. The function I've written simply renders the calculated points of a predetermined polygon in two dimensional space. These polygons are neither convex nor concave and thus I believe the name I should give the function is Render Uniform Polygon; however, I believe uniform may not be the correct word and could end up in a debate over the name. The function itself performs three actions to achieve the goal:




  1. Calculate the angle of each point $theta_n$.

  2. Calculate the new position $P_n$.

  3. Render a 3px by 3px dot at the new position.


The math for calculating $theta_n$ is:



$$theta_n = frac{biggl(bigl(frac{360°}{p}bigr)n + phibiggr)pi}{180°}$$



Where:





  • $p$ is the number of points in the polygon.


  • $n$ is the current point.


  • $phi$ is the global rotation angle.


Once $theta_n$ has been calculated with the math above, I then use it to calculate the new position with the following:



$$P_{_n{x, y}} = C_{x, y} + (cos(theta_n), sin(theta_n))r$$



Where:





  • $P_n$ is current point's position.


  • $C_{x, y}$ is the center of the polygon.


  • $r$ is the radius of the polygon.


This method can be used to render any polygon with three sides or more, and since the radius is predefined there isn't a case where the polygon can be convex or concave.





What is a polygon that is neither convex nor concave called?







terminology polygons






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 21 at 18:25









Adrian Keister

5,27371933




5,27371933










asked Jan 21 at 18:20









PerpetualJPerpetualJ

1767




1767








  • 1




    $begingroup$
    All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:22










  • $begingroup$
    @AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
    $endgroup$
    – PerpetualJ
    Jan 21 at 18:23








  • 1




    $begingroup$
    Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:25






  • 2




    $begingroup$
    For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
    $endgroup$
    – Ross Millikan
    Jan 21 at 18:25










  • $begingroup$
    @RossMillikan: Excellent point, I agree!
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:26














  • 1




    $begingroup$
    All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:22










  • $begingroup$
    @AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
    $endgroup$
    – PerpetualJ
    Jan 21 at 18:23








  • 1




    $begingroup$
    Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:25






  • 2




    $begingroup$
    For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
    $endgroup$
    – Ross Millikan
    Jan 21 at 18:25










  • $begingroup$
    @RossMillikan: Excellent point, I agree!
    $endgroup$
    – Adrian Keister
    Jan 21 at 18:26








1




1




$begingroup$
All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
$endgroup$
– Adrian Keister
Jan 21 at 18:22




$begingroup$
All regular polygons are convex. As far as I know, a polygon that is neither convex nor concave is called "neither convex nor concave". I don't know of any special term for that.
$endgroup$
– Adrian Keister
Jan 21 at 18:22












$begingroup$
@AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
$endgroup$
– PerpetualJ
Jan 21 at 18:23






$begingroup$
@AdrianKeister So simply Render Polygon should suffice in this case without causing any confusion?
$endgroup$
– PerpetualJ
Jan 21 at 18:23






1




1




$begingroup$
Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
$endgroup$
– Adrian Keister
Jan 21 at 18:25




$begingroup$
Sure! A regular polygon is a polygon, but not the reverse. So if you happen to be constructing regular polygons, a construct_polygon() method is a fine name for that.
$endgroup$
– Adrian Keister
Jan 21 at 18:25




2




2




$begingroup$
For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
$endgroup$
– Ross Millikan
Jan 21 at 18:25




$begingroup$
For me, a concave polygon is one that has at least one angle greater than $pi$ and a convex one has no angles greater than $pi$. In that case there are no polygons that are neither concave nor convex.
$endgroup$
– Ross Millikan
Jan 21 at 18:25












$begingroup$
@RossMillikan: Excellent point, I agree!
$endgroup$
– Adrian Keister
Jan 21 at 18:26




$begingroup$
@RossMillikan: Excellent point, I agree!
$endgroup$
– Adrian Keister
Jan 21 at 18:26










1 Answer
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$begingroup$

As far as I can see your polygon is convex. It's a regular polygon whose vertices are equidistant on the circle with radius $r$ and center $C$.






share|cite|improve this answer









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    1 Answer
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    active

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    2












    $begingroup$

    As far as I can see your polygon is convex. It's a regular polygon whose vertices are equidistant on the circle with radius $r$ and center $C$.






    share|cite|improve this answer









    $endgroup$


















      2












      $begingroup$

      As far as I can see your polygon is convex. It's a regular polygon whose vertices are equidistant on the circle with radius $r$ and center $C$.






      share|cite|improve this answer









      $endgroup$
















        2












        2








        2





        $begingroup$

        As far as I can see your polygon is convex. It's a regular polygon whose vertices are equidistant on the circle with radius $r$ and center $C$.






        share|cite|improve this answer









        $endgroup$



        As far as I can see your polygon is convex. It's a regular polygon whose vertices are equidistant on the circle with radius $r$ and center $C$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 21 at 18:25









        lightxbulblightxbulb

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