Go Back  Quiltingboard Forums > Main
Is there a method to calculate........ >

Is there a method to calculate........

Is there a method to calculate........

Old 01-20-2016, 02:25 AM
  #1  
Junior Member
Thread Starter
 
Vicki1212's Avatar
 
Join Date: Jul 2014
Location: Kwazulu Natal, South Africa
Posts: 265
Default Is there a method to calculate........

Is there a calculator or basic method of working out how many different combinations of HST's you can make from a set number of fabrics, for instance 12 fabrics? I am useless at maths and my brain goes into overdrive just trying to figure it out
Vicki1212 is offline  
Old 01-20-2016, 02:35 AM
  #2  
Super Member
 
117becca's Avatar
 
Join Date: Oct 2010
Location: dayton OH
Posts: 1,911
Default

i think 144.....12 x 12...........
117becca is offline  
Old 01-20-2016, 03:25 AM
  #3  
Super Member
 
bjchad's Avatar
 
Join Date: Nov 2010
Location: Southern New Jersey USA
Posts: 1,473
Default

The first fabric can be paired with 11 others, the next one with 10 others, the next with 9 etc. that is if you are looking for unique combinations.
bjchad is offline  
Old 01-20-2016, 05:26 AM
  #4  
Power Poster
 
Join Date: Dec 2010
Location: Michigan
Posts: 11,276
Default

Bjchad is correct. Start with 1, add 2 to that, then 3 etc. stop when you get to 1 less than the number of fabrics you have.
So lets say you have 6 fabrics. the number of unique HSTs would be 1+2+3+4+5 (the last number is the number of fabrics you have 6 minus 1 = 5).
PaperPrincess is offline  
Old 01-20-2016, 05:33 AM
  #5  
Power Poster
 
Join Date: Jun 2011
Location: Southern California
Posts: 19,131
Default

Something keeps ring in my brain. I think it is 132 but I could be wrong. One fabric becomes your main fabric and you will get 11 different HSTs. When you finish the quilt, tell us the answer.
ManiacQuilter2 is offline  
Old 01-20-2016, 07:33 AM
  #6  
Super Member
 
ghostrider's Avatar
 
Join Date: Jan 2009
Posts: 4,688
Default

It's called permutations and combinations in the math world. Permutations are where order matters, combinations are where it doesn't.
http://betterexplained.com/articles/...-combinations/

In your HST example, order doesn't matter, so it's a combination. And specifically how many combinations of r objects (2 in this case) from a set of n objects (12 in this case). Without getting into too much detail or terminology, the answer is 66.
12 11 2 1 = 132 2 = 66

Another example: if you wanted to know the number of different four patches you could make with 20 fabrics, it would be:
20 19 18 17 4 3 2 1 = 116,280 24 = 4,845

Have fun!

Last edited by ghostrider; 01-20-2016 at 07:37 AM.
ghostrider is offline  
Old 01-20-2016, 10:57 AM
  #7  
Super Member
 
Pennyhal's Avatar
 
Join Date: Oct 2010
Location: California
Posts: 1,726
Default

I have a book: Quilters Reference Tool written by Harriet Hargrave et al

It has tables and yardage...takes the math out of piecing

http://www.amazon.com/Illustrations-...rriet+hargrave

Also this one, but I haven't seen it, just found it online
https://www.byannie.com/shop/product/math-for-quilters/
Pennyhal is offline  
Old 01-20-2016, 03:18 PM
  #8  
Super Member
 
Join Date: Jul 2014
Location: Illinois
Posts: 2,140
Default

Are you counting each direction change? If so, you would have 300 possible combinations. If not, it's 75.
You need to add each consecutive number together to get the total. If you have 4 different layouts, then you need to also multiply the answer by 4.
12+11+10+9+8+7+6+5+4+3+2+1=75 | 75x4=300

Note: The above answer includes matching together 2 of the same fabrics (will look like a square of that fabric). If you don't want that option, get rid of the highest number.

11+10+9+8+7+6+5+4+3+2+1=63 | 63x4=252

squares.png
Bree123 is offline  
Old 01-20-2016, 07:41 PM
  #9  
Super Member
 
Join Date: Mar 2010
Location: greater NorthEast
Posts: 3,004
Default

Yikes, now i know why i like scrappy quilts so much -- there is no math!!!
just_the_scraps_m'am is offline  
Old 01-20-2016, 07:51 PM
  #10  
Super Member
 
Join Date: Aug 2013
Posts: 9,295
Default

If one quilter boarded a train from New York to Chicago at 3:45 pm with 27 yards of fabric And a long arm, , and another quilter boarded a train from Omaha to Chicago at 2:30 pm with 13 yards and a Featherweight, how much chocolate would they eat in Paducah?
zozee is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
NZquilter
Main
14
03-16-2018 08:17 AM
HomespunHandmaiden
Main
8
10-29-2011 01:33 AM
Maggiesmom
Pictures
68
03-23-2011 07:02 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


FREE Quilting Newsletter


SEO by vBSEO ©2011, Crawlability, Inc.