Ok. I am being burdened by my ignorance that its creating more questions
than I can handle. What I mean is that I now have a feeling that I am
solving the problem the wrong way. I am going to explain the problem as
a whole so that I can get an idea on how advanced J programmers would
solve it. You can also see from my explanations below how I use J to
solve problems too. Any advice/criticism are welcome and appreciated.
What I am doing right now is reviewing my existing codes and trying to
optimize them by removing the for loops. This came about when I had a
complaint from some of my users that some operations were taking around
30 minutes to complete. The code below is running fine but I'm using it
as an example because this type of loop is prevalent in my projects:
NB. ======== START OF CODE ========
NB. STEP 1d: Make copies of DUV by the number of destination declared
sids=. searchLOOKUP 'DUV'
masks=. (BOM_USAGE_CLASS colsfrom bomv) member sids
if. sum across masks do.
NB. STEP 1b1: Work only with rows that matches
wrkbom=. masks copy bomv
wrkvbom=. (0,behead shape wrkbom) shape 0
for_data. wrkbom do.
NB. Check if we have a UV Summary defined for current GMC
msk=. (atomize BOM_GEN_MAT_ID colsfrom data) = DUV_GEN_MAT_ID
colsfrom DUVV
if. tally where msk do.
NB. Copy the current bom to the number of defined destination
temp=. (tally where msk) copy tomatrix data
NB. Update the destination code to the ship to customer code
wired=. DUV_CUSTOMER_CODE colsfrom DUVV selectrows where msk
if. 1 = shape wired do.
wired=. atomize wired
end.
temp=. temp replacecols BOM_DESTN_CODE;wired
NB. Now save the current bom
wrkvbom=. wrkvbom atop temp
end.
end.
NB. Now remove the processed bom's then add the new BOM's
bomv=. bomv selectrows where not masks
bomv=. bomv atop wrkvbom
end.
NB. ======== END OF CODE ========
First off, I know that you'll be horrified because it doesn't look like
any J script that you know. :P Hehehehehehe.
In summary, what this code does is expands a list of materials to the
number of destination. To illustrate, take the following data:
NB. List of Destination by Generic Material ID:
DUV_FIELDNAMES,DUVD
+--------------+-------------+-----------------+
|DUV_GEN_MAT_ID|DUV_CITY_CODE|DUV_CUSTOMER_CODE|
+--------------+-------------+-----------------+
|1002091 |OSAKA |0000020071 |
+--------------+-------------+-----------------+
|1002091 |NODA - SHI |0000020073 |
+--------------+-------------+-----------------+
NB. The numeric equivalent of the data above is:
DUVV
1002091 195 156
1002091 196 157
NB. List of Materials
(<:BOM_USAGE_CLASS,BOM_GEN_MAT_ID,BOM_DESTN_CODE) { "1
BOM_FIELDNAMES,ADBOMDTLD
+---------------+--------------+--------------+
|BOM_USAGE_CLASS|BOM_GEN_MAT_ID|BOM_DESTN_CODE|
+---------------+--------------+--------------+
|DUV |1002091 | |
+---------------+--------------+--------------+
(<:BOM_USAGE_CLASS,BOM_GEN_MAT_ID,BOM_DESTN_CODE) { "1 ADBOMDTLV
139 1002091 0
NB. Result of operation
(<:BOM_USAGE_CLASS,BOM_GEN_MAT_ID,BOM_DESTN_CODE) { "1
BOM_FIELDNAMES,BCONSUMPD
+---------------+--------------+--------------+
|BOM_USAGE_CLASS|BOM_GEN_MAT_ID|BOM_DESTN_CODE|
+---------------+--------------+--------------+
|DUV |1002091 |0000020071 |
+---------------+--------------+--------------+
|DUV |1002091 |0000020073 |
+---------------+--------------+--------------+
(<:BOM_USAGE_CLASS,BOM_GEN_MAT_ID,BOM_DESTN_CODE) { "1 BCONSUMPV
139 1002091 156
139 1002091 157
So basically, the code above takes the list of materials and the number
of matching destination and combine them. So in this case, we only get
two resulting records because we only have 1 material and 2 destination.
There will be cases where the list of materials will have repeating
BOM_GEN_MAT_ID or a material that does not match any entry in the
destination.
As you can see, my approach is using traditional programming technique
where I would loop through the list of materials and check if there is a
matching material in the destination. If there are, I would then
replicate the material to the number of matching destination and copy
the DUV_CUSTOMER_CODE to the BOM_DESTN_CODE as is, otherwise I'll just
continue to the next material in the list.
Unfortunately, this is only for BOM_USAGE_CLASS of DUV or by
Destination. I also have permutations of this like:
1. SUV - by size
2. SDUV - by size and destination
3. AUV - by article
4. ASDUV - by article, size and destination
5. ASSTPOUV - by article, size, sub-style, and purchase order
6. etc.
The combination of Usage Class is mind boggling and the merchandisers
are coming up with new ways to make my life difficult. So here is the
problem, I think I am using J to solve the problem the wrong way. For
example, for ASDUV, I would loop by:
NB. Pseudo code
for_article. articles do.
NB. Do something for articles
for_size. sizes do.
NB. Do something for sizes
for_destination. destinations do.
NB. Do something for destination and save it
end.
NB. Save changes for size and destination
end.
NB. Save changes for colorway, size and destination
end.
So as you can see, I'll be looping 3 levels deep and one local variable
for each level and updates to the parent variable until the whole
operation is complete.
As I said, any suggestion, insights and/or criticism are appreciated.
Thanks.
r/Alex
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