min/max limits conception

vsbus / fmadvcalc

Automatically exported from code.google.com/p/fmadvcalc

0 stars 0 forks source link

min/max limits conception #17

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago

on 30-06-2010 we discussed how to get min/max limits. 
I implemented partitially this conception and got next problems:
1. sometimes limits for parameter illegal. Maybe there is really empty set of 
correct parameters or it is very small (smaller than (rangeMax - rangeMin)/1000 
). And it is unclear what to display in this situation.

2. If some parameters are not entered then it can take too much time to check 
all combinations of inputs. And trying to use min/max values can lead to wrong 
results sometimes.

Original issue reported on code.google.com by victorbarinov on 30 Jun 2010 at 12:54

GoogleCodeExporter commented 9 years ago

3. Sometimes there can be a set of independent parameters and if in one set 
inputs are out of restrictions but in the other they can be inside program 
can't recognize such case and shows that for second class of parameters empty 
set of valid inputs...

Original comment by victorbarinov on 30 Jun 2010 at 1:35

GoogleCodeExporter commented 9 years ago

4. Problem with values near min or max.

Original comment by victorbarinov on 30 Jun 2010 at 2:24

GoogleCodeExporter commented 9 years ago

5. Sometimes program can't find min/max because it is too small. Then user can 
change range and solution will be found. Or program can be improved to do it 
iteratively

Original comment by victorbarinov on 30 Jun 2010 at 2:31

GoogleCodeExporter commented 9 years ago

The best way to speed up search of min/max range is to:
1. set best ranges in restrictions (as small b - a then better)
2. impelemt binary search (separately for min and for max). That is little more 
complicated solution but more powerfull. But I also not sure that bin search 
always will work correctly. (I ahve doubts regarding monotonicity of the 
functions)

Original comment by victorbarinov on 30 Jun 2010 at 3:47

GoogleCodeExporter commented 9 years ago

6. It is wrong to use min/max from restrictions in case if parameter is not 
defined. For example for Standart1 it can be

Original comment by victorbarinov on 30 Jun 2010 at 4:30

GoogleCodeExporter commented 9 years ago

After some ivestigations I found that all functions are constants, monotonic or 
with only one extremum point. So I will use something like gradient search.

Original comment by victorbarinov on 8 Jul 2010 at 8:32

GoogleCodeExporter commented 9 years ago

Test for tr

Original comment by victorbarinov on 8 Jul 2010 at 8:32

Attachments:

wrong_tr_max.PNG

GoogleCodeExporter commented 9 years ago

I have implemented combination of bisection and check of gradient methods and 
god good calculations.

Original comment by victorbarinov on 11 Jul 2010 at 7:08

GoogleCodeExporter commented 9 years ago

I found a problem connected with assuming that negative values are not OK.

Original comment by victorbarinov on 12 Jul 2010 at 7:40

Attachments:

tc_limits_wrong.PNG

GoogleCodeExporter commented 9 years ago

Previous problem was fixed by not checking negative values for first limit. But 
problems are still exists. For eaxmple this one(Optimization1):

Original comment by victorbarinov on 12 Jul 2010 at 7:58

Attachments:

tr_limits_wrong.PNG