Forum Discussion
Convex hull Lambda > would it be impossible to build?
Hello everyone, Ever since visiting the site of Andy Pope, I saw a chart that fascinated me because it can be very useful for creating the bounding area of a set of points. It's known as Convex ...
I'm a hardcore ALT + ENTER + Space Bar kind of guy, so formatting formulas to be vertically is imperative for me. And in reviewing the formula, I have to ask, what´s this %% (double percentages)? And also, what's this secret function =RAD() ?
note: I'm not a LAMBDA expert like the brilliant minds that have posted here. Yet, I'm always eager to learn the -- core concepts -- of interesting and complex formulas.
z is column 1 is X , column 2 is Y
XMATCH(0,DROP(z,,1)-TAKE(z,,1)%%,1) => XMATCH(0,Y-X%%,1)
% is divided by 100
Y - X /100 /100 This is to get the lowest point on Y and max point on X
if we have
x10,y5 x10, y1 and x100 y1 this will give you the x100 y1 the bottom right point
but I realize that is not necessary. any bottom y point will work.
RAD,LAMBDA(p,q,ATAN2(INDEX(q,1)-INDEX(p,1),INDEX(q,2)-INDEX(p,2)))
This is the Lambda function to calculate the angle in radians of 2 points from P and Q.
XMATCH(0,DROP(z,,1)-TAKE(z,,1)%%,1) => XMATCH(0,Y-X%%,1)
% is divided by 100
Y - X /100 /100 This is to get the lowest point on Y and max point on X
if we have
x10,y5 x10, y1 and x100 y1 this will give you the x100 y1 the bottom right point
but I realize that is not necessary. any bottom y point will work.
RAD,LAMBDA(p,q,ATAN2(INDEX(q,1)-INDEX(p,1),INDEX(q,2)-INDEX(p,2)))
This is the Lambda function to calculate the angle in radians of 2 points from P and Q.
Bo, right now I'm like a little kid with a new toy. Thank you for this! You leave me with good homework to study this mind-blowing formula. I'm attaching this updated version with pivot table slicers for switching the set of dots.
Lastly, I have messaged Andy Pope about this post on this forum.