Hi Richard,
You are in the south hemisphere, so ! Temperatures are low here in France.
Thank you for your comments.
I agree that development is slow if you look at the plant every day, and
in this case we perceive continuous changes. But in models, it might be
convenient to define discrete stages. If you look at a flower bud at a
given date and come back several days (or weeks) after, you can see a
flower at the bud location. This type of approximation is usual in
biological modelling and data acquisition.
Thank you for the suggestions on the "State" design pattern. I will have
a look !
Loïc
Le 16/01/2019 à 13:18, Richard O'Keefe a écrit :
It seems to me that in the real world, a bud does not get replaced by
a flower
nor a flower by a fruit, nor is there a definite point at which a
thing stops
being a bud and starts being a flower, and so on. It's summer now,
but spring
wasn't that long ago, and I enjoyed watching the imperceptible
*continuous*
changes. So anything you do is going to be imposing discontinuity on
a more-
or-less continuous process and is definitely going to be an approximation.
You may perhaps be looking for the "State" design pattern where there
is an
object with a fixed identity (*this* bud/flower/fruit) which behaves
differently at different times, and this is modelled by the "outer" object
delegating some of its behaviour to a "state" which can be replaced.
So you would have
PlantOrgan
PlantReproductiveOrgan (state)
PlantReproductiveOrganState
Bud
Flower
DeadFlower
ImmatureFruit
MatureFruit
You will find abundant material about the "State" design pattern on
the web.
On Thu, 17 Jan 2019 at 00:29, Loïc Pagès <loic.pa...@inra.fr
<mailto:loic.pa...@inra.fr>> wrote:
Hi Joachim,
Thank you for your reply and for your ideas. I will reply to your
questions below.
Le 16/01/2019 à 10:25, jtuc...@objektfabrik.de
<mailto:jtuc...@objektfabrik.de> a écrit :
> Loïc,
>
> Am I correct in assuming you are thinking about a model in which a
> plant can have a growing and shrinking list of organs over time and
> some of them even have (a growing list of) stages?
Yes, the plant can be seen as a growing and shrinking list of organs.
Very short list at the beginning, and becoming larger. Some organs
can
fall (leaves, roots) or even be pruned (shoots in fruit trees), so
that
shrinking can also occur.
However, the list of stages for each organ is usually known at the
beginning, for each type of organ. It depends of knowledge and
level of
detail that we include in the model.
>
> I am not an expert on the matter, but to me the stages idea sounds
> good. It even allows for historic information (it was a bud from
Date1
> to Date2 and since then it is a flower). So transformation would be
> adding a new Stage and "terminate" the previous one.
This can be an approach. But the conditions for passing from one
stage
to another can be more complex and involve several aspects (age,
previous growth, pollination, etc) with a lot of code. So, if you
keep
this code into the general "reproductive organ" class, you make a
"fat
class" with a lot of tests. This was not recommended in the Pharo
course
:-)
>
> With this you can ask a plant about its current stage on the
> reproductive front and maybe other organs as well at any point
time.
> This may be helpful if you want to build an animation of the
plant's
> development over time. You can have separate life cycles for
each organ.
This is actually an objective of such models, to be able to get the
status of the whole plant, regarding the stages of organs.
>
> Does the plant transform in the real world? I mean, is a cherry
tree
> still a cherry tree, even if it's not blooming any more and carries
> fruit instead? So why transform the object in its abstract model?
The plant usually changes because of its development, but a cherry
tree
remains a cherry tree ! And flowers are necessary steps to get
fruits
! The idea was not to transform the whole plant, but each individual
organ that it carries.
>
>
> Just a thought, maybe better ideas show up.
OK, thank you again
Loïc
>
>
>
> Am 16.01.19 um 10:15 schrieb Loïc Pagès:
>> Dear Pharo users,
>>
>> I develop software dedicated to the simulation of plant
development
>> and 3D architecture.
>>
>> In the past, I used Java, but I am very interested in translating
>> code in Pharo. I appreciated very much the language and the course.
>>
>> I have a question for you all :
>>
>> During plant development (ontogeny), new organs appear, that are
>> gradually tranformed. For example, a bud can make a flower, and
then
>> a fruit.
>>
>> Organs are conveniently modelled as classes. During the course, I
>> learned that it was better to make several classes (bud, flower,
>> fruit) instead of a "fat class" such as "reproductive organ" with
>> many attributes and stages (bud stage, flower stage, fruit
stage). I
>> wonder how to transform an object into another one, to
represent for
>> example the fact that the flower may become a fruit.
>>
>> Maybe a naive question ?
>>
>> Thanks for your lights !
>>
>> Loïc
>>
>>
>>
>>
>
>
