Re: [Miase-discuss] OM changed

[Frank B. <fbergman@u.washington.edu>]

>
>> Other changes do require discussion, as I'm not quite sure what to  
>> do with
>> them:
>>
>> Previously logX and logY were properties of a Plot2D, as facility of
>> creating a log plot. In the current version those attributes are now
>> properties of the *individual* curves of the plot. Is this really  
>> necessary?
>
> Yes, we found examples where curves with linear and log Y where  
> plotted together.
>> Does it make sense to paint those together? And what is supposed to  
>> be on
>> the axis, the logged values or the uhm not-logged ones?
>
> You have plenty of plots with several axis, for instance on the left  
> and on the right.
>

It just felt like this would make the live of everyone implementing  
the spec much harder :) Also the same effect could be easily achieved  
by separate plots overlaid. Remember the plot is not fully annotated,  
as we don't use axis labels. And so it might be hard on readers of  
such graphs as well. Could you link to some examples? Just to get a  
better picture.

>> Or previously we had Parameter values defined as real-numbered  
>> values, now
>> they are strings.
>
> I do not remember when this happened, and actually did not notice. I  
> find this odd and I agree we should discuss it.
>

In that case I'm all in favor of using real-numbered values as  
parameters :)

>> Finally some of the classes that were previously under discussion,  
>> hence
>> marked white are now no longer marked.
>
> It is just a coloring trick I believe.
>
>
>> 	I.e: ChangeMath, here I'm not sure what the list of variables, or
>> list of parameters would be? I thought this would be a special case  
>> of
>> changeXML, where I just swap out one snippet of MathML by another  
>> one. But I
>> would not know what to do with variables and parameters in that case.
>
> This is a big misunderstanding. ChangeXML is used to replace a piece  
> of the model by something else. One can replace the value of an  
> attribute, or an element etc.
>

that much seems clear

> ChangeMath COMPUTES a change. For instance, you can compute the new  
> value for an attribute of model A based on the value of an attribute  
> of model B and an external parameter. Therefore the listOfVariables  
> use an XPath.

I remember a post about this from way back. I still don't quite  
follow. An example here would really help. To me it seems like this is  
an added complication we don't need. At the time of writing, the tool  
writing the ChangeMath will have to know about model B and the  
external parameter, hence this could be written as  
<changeAttribute ... sparing the reader the complications, of sorting  
out the math, resolving the model it belongs to (which again might be  
in a model format, the reader does not understand)

best
Frank