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ioam / topographica

A general-purpose neural simulator focusing on topographic maps.
topographica.org
BSD 3-Clause "New" or "Revised" License
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a mistake in the User Manuel #547

Closed kalok87 closed 10 years ago

kalok87 commented 10 years ago

Dear Developers,

In the chapter 'Generating patterns' of the User Manuel, there could be a mistake in the second part of 'Composite patterns'.

If we follow the output, we are supposed to have output: centersurround

But however, what I am getting is this one: figure_3

I think the reason for this is that we use numpy.add as the operator in the last command,

pattern.Composite( generators[center,surround], operator=numpy.add, xdensity=160,ydensity=160)

jbednar commented 10 years ago

That's very strange -- are you sure you followed all of the steps? I just tried it on one of our machines, and I get the picture you have at the top. Numpy.add should be ok in this case, because the surround is meant to be a grating ring, not a grating disk -- try doing matrixplot(surround()) to see. Maybe you left off the numpy.subtract operator from the surroundring? You can plot each step as you do it, and will probably see the problem, because clearly in your version the center has not successfully been subtracted out or multiplied out from the surround grating.