🚀 go-pugleaf

I am having a problem with th euse of
image and image.legend and would be
interested in getting some feedback

I have a model that produces x,y,z data for
different times of day.  I have no problem
getting the image on the screen, or getting
output.  The problem is this.  The range for
values of z varies with the time of day.  At
night the range is small, 1-2 units, while
during the day it si quite large, 10-20 units. 
What I would like to do is produce a series
of images of the data for each time and
have a legend on each image that is the
same.  In addition I would like image to use
the same greay scales for each value of z
on all of the images.  I can not seem to
figure out how to control the number of
greyscales on an image or the range of data
to plot.  Does anyone have any words of
advice?


steve lowe
D