Consistent xticks,yticks

Hi there, I am using a 'for loop' to generate multiple

    > scatter plots from my data. So far, so good.

    > I would like to have consistent xticks and yticks for each
    > scatter plot. However, it seems that when I define xticks
    > and yticks (remains the same for each scatter plot), I get
    > different xticks and yticks for each scatterplot depending
    > on the data.

    > How can I make the xticks and yticks consistent over ALL my
    > scatterplots, regardless of the data used to generate them?

some thing like:

xvals = 1,2,3
yvals = 4,5,6

for data in mydata:
    fig = figure(1)
    ax = fig.add_subplot(111)
    ax.scatter(blah, blah, data)