using weights

[jaz]

I'm really enjoying using this website to fit many of my curves. It's
REALLY helpful.

However, i want to know how to include the weighting in the text data
editor.
Lets say i have 2 columns of data, x and y. I know the errors in y, so
how do i include this in the text data editor?

[zunzun.com]

From the example data:

Weighted fitting requires an additional number to
be used as a weight when fitting. The site does
not calculate any weights, which are used as:
error = weight * (predicted - actual)
You must provide any weights you wish to use.

So your data would be entered as:

X Y Weight
5.357 0.376 0.5
5.457 0.489 0.5
5.797 0.874 1.0

etc., etc.

James

[Andrew MUNDT]

I am having some trouble using weights too. I have set up the data in the format shown and tried to use Function Finder on 3D data. However, it always gets stuck at "Scanned 1 Equations : 1 OK, 0 skipped, 0 exceptions" and sits there. My data (115 triplets + weights is below). I have tried truncated the set and finds it Function Finder works as expected through x = 3.25. However, when x = 3.5 or beyond, Function Finder gets stuck with the message as above. Trying various smoothness values yields similar errors with different numbers of equations in the error, but he same result. Any help would be appreciated.

X    Y      Z     Wgt
2    17    0.00    0.13
2    18    0.00    0.26
2    24    1.00    0.13
2.25    16    0.00    0.13
2.25    17    0.00    0.13
2.25    18    0.00    0.13
2.25    22    0.33    0.40
2.25    23    0.00    0.26
2.25    25    0.00    0.13
2.5    15    0.00    0.26
2.5    18    0.00    0.13
2.5    19    0.50    0.26
2.5    20    0.00    0.66
2.5    21    0.50    0.26
2.5    22    0.50    0.26
2.5    23    0.67    0.40
2.5    24    0.00    0.13
2.75    16    0.20    0.66
2.75    17    0.50    0.79
2.75    18    0.00    0.26
2.75    19    0.67    0.79
2.75    20    0.13    1.06
2.75    21    0.67    0.40
2.75    22    0.67    0.40
2.75    23    0.42    1.59
2.75    24    0.43    0.93
2.75    25    0.00    0.13
2.75    26    1.00    0.13
2.75    27    1.00    0.13
3    13    0.50    0.26
3    14    0.00    0.26
3    15    0.50    0.26
3    16    0.00    0.79
3    17    0.33    0.79
3    18    0.67    0.40
3    19    0.67    0.40
3    20    0.73    1.98
3    21    0.40    1.32
3    22    0.75    1.06
3    23    0.64    1.46
3    24    0.71    1.85
3    25    0.60    1.32
3    26    0.50    0.79
3    27    0.50    0.53
3    28    0.50    0.26
3    29    1.00    0.13
3    33    1.00    0.13
3.25    16    0.67    0.40
3.25    17    0.50    0.26
3.25    18    1.00    0.13
3.25    19    0.43    0.93
3.25    20    0.33    1.19
3.25    21    0.42    1.59
3.25    22    0.56    1.19
3.25    23    0.80    2.65
3.25    24    0.64    1.46
3.25    25    0.73    1.46
3.25    26    0.69    1.72
3.25    27    0.67    1.19
3.25    28    0.91    1.46
3.25    29    0.75    0.53
3.25    30    1.00    0.13
3.25    31    1.00    0.13
3.5    17    1.00    0.40
3.5    18    0.80    0.66
3.5    19    0.67    0.40
3.5    20    0.67    0.79
3.5    21    0.86    0.93
3.5    22    0.75    1.59
3.5    23    0.82    1.46
3.5    24    0.93    1.98
3.5    25    0.69    2.12
3.5    26    0.89    3.57
3.5    27    0.83    2.38
3.5    28    0.92    1.72
3.5    29    0.86    0.93
3.5    30    1.00    0.66
3.5    31    1.00    0.40
3.5    32    1.00    0.53
3.5    33    1.00    0.13
3.5    34    1.00    0.13
3.5    35    1.00    0.13
3.75    18    1.00    0.13
3.75    19    0.50    0.26
3.75    20    0.75    0.53
3.75    21    1.00    0.79
3.75    22    0.89    1.19
3.75    23    1.00    1.46
3.75    24    0.95    2.65
3.75    25    1.00    2.12
3.75    26    0.96    3.57
3.75    27    1.00    2.51
3.75    28    1.00    3.97
3.75    29    0.90    2.78
3.75    30    1.00    1.46
3.75    31    1.00    1.98
3.75    32    1.00    0.93
3.75    33    1.00    1.72
3.75    34    0.78    1.19
3.75    35    1.00    0.13
3.75    36    1.00    0.13
4    22    1.00    0.26
4    24    1.00    0.66
4    25    1.00    0.26
4    26    1.00    0.40
4    27    1.00    1.32
4    28    1.00    0.93
4    29    1.00    0.26
4    30    1.00    0.93
4    31    1.00    1.59
4    32    1.00    0.53
4    33    1.00    0.13
4    34    1.00    0.26
4    35    1.00    0.13
4    36    1.00    0.13

Thanks!

              - - - Andrew

[zunzun.com]

Thank you for the data and description.  I will investigate and keep you updated.

 

     James

On Wednesday, April 11, 2012 10:27:26 AM UTC-5, Andrew MUNDT wrote:

I am having some trouble using weights too...

[zunzun.com]

I verified that both the 2D and 3D Function Finders do not work with weighted fitting on, so you have indeed found a problem with the site code.  I am continueing to investigate.

 

James

[zunzun.com]

I have verified that the problem is not in the site fitting code:

 

http://code.google.com/p/pyeq2/

 

which means it is isolated to the web site itself.

 

     James

[zunzun.com]

This is now working in my tests, please try now.

James

[zunzun.com]

Did it work for you?

 

     James