Re: [Jmol-users] do color schemes fail with large data ranges?

[Bob H. <ha...@st...>]

Timothy Driscoll wrote:

>
>Bob, can you explain how Jmol assigns colors in the case of an  
>external data set?  for example, the roygb scheme.  I assume Jmol  
>breaks up the entire data range into 5 equal sections, and applies  
>one color to each section.  (for the bwr scheme, it would be three  
>instead of five sections.)  is this correct?
>
>  
>
The overall range of the data is found, and the values from minumum to 
maximum are binned into as many bins as there are colors listed in the 
color scheme. Then the appropriate color is assigned. If you set the 
absolute range of the color scheme, then you are changing the two 
numbers used for minimum and maximum ("red" and "blue"). In this way you 
can focus on any range you want and ignore the others -- they either 
appear red or blue because they are off-scale.


>if so, I can dispense with binning the data and look into  
>transforming them into a normal distribution.
>
>
>  
>
If you want something like a logarithmic scale, you have to bin those 
--- or supply the logarithmic number. Sorry, no LN function in Jmol math!

Bob


>cheers,
>
>tim
>  
>


-- 
Robert M. Hanson
Professor of Chemistry
St. Olaf College
Northfield, MN
http://www.stolaf.edu/people/hansonr


If nature does not answer first what we want,
it is better to take what answer we get. 

-- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900