The mask command only sets values to zero. Should have an option to specify the fill value. But lacking that I suggest using “vop scale” to shift the map by 128 and make the new value type unsigned 8-bit assuming it is currently signed 8 bit (vop scale #3 shift 128 valueType uint8 model #4). Then mask, then shift back if you prefer the signed values. In ChimeraX I’ll make mask and erase operations capable of specifying a fill value different from 0. Tom

On Jun 2, 2016, at 4:44 PM, Dougherty, Matthew T <matthewd@bcm.edu <mailto:matthewd@bcm.edu>> wrote:

I have a volume whose density values are -127 thru 127. Zero is a valid density & approximately the peak of the Guassian distribution.

I would like to use the command mask. It sets the unmasked density values to zero. How can I set the unmasked density values to -128 using the mask command? Will I need to hack the code?

Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ================================================= ================================================= _______________________________________________ Chimera-users mailing list: Chimera-users@cgl.ucsf.edu <mailto:Chimera-users@cgl.ucsf.edu> Manage subscription: http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users <http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users>