thanks!  That clarifies the issue.

- atif

On 3/25/2009 8:12 AM, Jennifer Jackson wrote:
> Hello,
> Please see our documentation
> http://genome.ucsc.edu/goldenPath/help/chain.html
> http://genomewiki.ucsc.edu/index.php/Coordinate_Transforms
>
> The coordinates for this chr20 chain are in the (-) strand. Chain file 
> formats are different from many of our other file formats in that they 
> are based on the reverse-complement strand (not converted to be 
> positive strand). However, they are still ordered smallest -> largest 
> in value. And the smallest coordinate is still zero-based. These chain 
> coordinates are converted to be positive stranded and to be a 1-based 
> start when displayed in the browser chain description page.
>
> The chromosome 20 length is: 62,435,964
>
> Doing the math to compare the browser data points to the chain file 
> data points:
>
> start: 62435964 - 19465389 = 42970575
> end: 62435964 - 19472380 = 42963584 +1 (to convert the zero-based 
> "smallest" coordinate) = 42963585
>
> I hope I have addressed all of your questions, but let me know if I 
> missed anything,
> Jennifer Jackson
> UCSC Genome Bioinformatics Group
>
> Atif Shahab wrote:
>>
>> Sorry copied the wrong row.  Following is the row I find in 
>> chr11.chainSelf
>>
>> 725, 212246, 'chr11', 134452384, 18466024, 18469085, 'chr20', 
>> 62435964, '-', 19465389, 19472380, 80309, 77.2
>>
>> while what I see in UCSC browser is
>>
>> *Human position:* chr11:18466025-18469085 size: 3061
>> *Strand:* -
>> *Human position: * chr20:42963585-42970575 
>> <http://ucsc.gis.a-star.edu.sg/cgi-bin/hgTracks?db=hg18&position=chr20%3A42963585-42970575>
>>  
>> size: 6991
>> *Chain ID:* 80309
>> *Score:* 212246 *Approximate Score within browser window:* 1240
>>
>> The browser reports reports the position to be in 
>> chr20:42963585-42970575 while what I get from the chr11.chainSelf is 
>> chr20:19465389-19472380.
>>
>> - atif
>>
>> On 3/24/2009 2:44 AM, Jennifer Jackson wrote:
>>> Hello,
>>>
>>> The data reported for the region chr11:56259903-56260492 on the 
>>> track description page represents a subset of the data from the 
>>> entire chain record (chr11_chainSelf.id = 1118118). That is why the 
>>> score is approximate. The track description page explains the 
>>> display conventions in the Description section.
>>>
>>> We hope this helps to explain the data,
>>> Jennifer Jackson
>>> UCSC Genome Bioinformatics Group
>>>
>>>
>>>
>>>
>>>
>>> Atif Shahab wrote:
>>>> Hi,
>>>>
>>>> In the UCSC browser I get the following info
>>>>
>>>> *Human position:* chr11:56259903-56260492 size: 590
>>>> *Strand:* -
>>>> *Human position: * chr20:56904056-56908860 
>>>> <http://ucsc.gis.a-star.edu.sg/cgi-bin/hgTracks?db=hg18&position=chr20%3A56904056-56908860>
>>>>  
>>>> size: 4805
>>>> *Chain ID:* 1118118
>>>> *Score:* 38233 *Approximate Score within browser window:* 2221
>>>>
>>>> But when I look into the mysql table for chr11.  I find the following
>>>>
>>>> 725, 212246, 'chr11', 134452384, 18466024, 18469085, 'chr20', 
>>>> 62435964, '-', 19465389, 19472380, 80309, 77.2
>>>>
>>>> Notice that the chr20 start/end are different from what is show in 
>>>> the browser.  Does the browser use some formula to compute the 
>>>> start/end?
>>>>
>>>> Also the chain track displays boxes joined by single/double lines.  
>>>> Which table contains the info regarding the start/end positions of 
>>>> these boxes?
>>>>
>>>> - atif
>>>> _______________________________________________
>>>> Genome maillist  -  [email protected]
>>>> http://www.soe.ucsc.edu/mailman/listinfo/genome
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