Hypsometric shading colour allocation

tjhb

Mike,

There may be a discrepancy in the way hypsometric colours are allocated to heights using a custom palette. (Version 10.02, build 5 June 2009.)

The manual says,

If the blend colors option is not checked, any elevation between two elevation values will be set to the color associated with the lower of the elevation values.

To reflect current behaviour, I think this should instead say,

If the blend colors option is not checked, any elevation between two elevation values will be set to the color associated with the nearer to zero of the elevation values.

(Heights above zero behave in accordance with either formulation.)

For example, if I set height -200 to RGB (0, 0, 220), and height -400 to RGB (0, 0, 200), then from the manual I would expect heights falling between -200 and -400 to be given the second colour, corresponding to the lower height.

Instead, they are given the first colour (higher, but nearer to zero).

If this is right, then I don't know whether you'd rather change the manual, or the behaviour of the code.

Tim Baigent
Wellington, New Zealand

tjhb

I'm really not sure I was right about this. I might have been doing something strange with my data.

So please ignore the original post for the time being. I'll check.