Re: Re digital data
This message: [ Message body ] [ More options ]
Related messages: [ Next message ] [ Previous message ] [ In reply
to ]
From: WEHICytometry <facs_copy@[EMAIL PROTECTED]
>
Date: Tue Mar 14 2006 - 23:28:16 EST
On 14/03/2006, at 9:03 AM, Mario Roederer wrote:
> Actually, there aren't several transforms -- basically there are
> only two ("Logicle", from Dave Parks and Wayne Moore at Stanford,
> used by DiVa and FlowJo; and the "HyperLog" from Bruce Bagwell at
> Verity used by WinList). And, in fact, these two are
> mathematically nearly identical; the Logicle function is a slightly
> more complex, and slightly smoother version, but probably without
> noticeable visual difference when the same parameters to the
> function are used. The primary difference between the two is that
> the Logicle algorithm provides for a mechanism to automatically
> select parameters to the function that are optimized to the actual
> distribution of the data--hence, the transformation can, if
> desired, be stronger or weaker for one fluorescence channel than
> for another (which is reasonable, as the magnitude of the error in
> the measurement is very different in these channels, and the error
> in the measurement is the primary reason we need the transforms!).
>
I feel obliged to correct Mario there; there are indeed more than
two. Another is the "split scale" form that is used in the WEASEL
fcm analysis and display program (see http://www.wehi.edu.au/
cytometry/WEASELv2.html). This transform is mathematically simpler
but, I assert, no less valid. It has been used in WEASEL for a year
or so and was described to the Australasian Flow Cytometry Group
last
year (see the abstract at http://www.wehi.edu.au/cytometry/Abstracts/
AFCG05B.html).
Frank.
| | << The Cytometry Laboratory
\__/ <<<< The Walter & Eliza Hall Institute
------!!<<<<<< 1G Royal Parade, Parkville
/!!\ <<<< Victoria 3050, Australia
o !! \ << ph: 61_3_9345 2540, fax: 61_3_9347 0852
Received on Wed Mar 15 16:18:00 2006
This message: [ Message body ]
Next message: Matt Gordon: "Re: Fixation of cells for TUNEL assay"
Previous message: Carol Oxford: "LSRII pressurized waste tank"
In reply to: Mario Roederer: "Re: Re digital data"
Contem****ary messages sorted: [ By Date ] [ By Thread ] [ By Subject ]
[ By Author ] [ By messages with attachments ]
This archive was generated by hypermail 2.1.8 : Thu Mar 16 2006 -
03:12:01 EST
|
