Tips and Tricks - best practice with JMP/JSL

[#1]

There is a wonderful blog post by @Craige_Hales : How Do You Draw a Circle? 

It nicely illustrates that there are multiple solutions to every problem - with varying degrees of success in achieving the goal and in investing ressources.

And often there is not the ONE solution with maximum points in all categories:

• goal was met
• length of code
• speed (to write the code)
• speed (to execute the code)
• complexity (to understand the code)
• complexity ( to remember the code)

Examples:

topic	standard approach	faster/optimized approaches	links
General
learn scripting	trial and error	watch the recordings of theJSL Scripters Club Meetings
Data import
open multiple data files	use open()  (inside a for loop)	use MFI (faster csv reader!)	Open multiple Files
get a list of files	generate the file list - via Python, command prompt etc. and paste it into a new JMP table	MFI → right click on file list → Make into data table
find a file in a deep/complicated network tree structure	use MFI or Windows File dialog	create a wrapper for Python/GLOB
Data tables
change column entries	step by step via for loop	data table subscripting	Data table subscripting
	...	dt << begin/end data update; before/after the loop	Very slow loop behaviour
add columns to a data table	merge data tables via Tables/Update	first aggregate via Tables/Summary,  then merge via Tables/Update	Speed up Tables/Update
column aggregation with restrictions	with a character comparison Col(if(... gets very (!!!) slow: col Max( if(:sex=="M", ...)	a) use if(:sex==1,...)	How-do-I-use-the-Col-Maximum-Formula-with-a-where   (fixed in V19)
	...	b) replace :sex=="M" with contains(:sex,"M")	How-do-I-use-the-Col-Maximum-Formula-with-a-where
count words	e.g. count xxx in :col: N Rows(loc(Words(:col),"xxx"))	(Length(:col)- Length(Substitute(:col, "xxx", "")) )/3​	Count number of occurrences of specific words in a string
rank unique	New Column( "rank_unique", Formula( Col Minimum( Col Rank( If( Row() == Col Min( Row(), :age, :sex ), 1 ), :age ), :age,:sex))	Col Score(:age, :sex) (v19)	Add dense ranking to Ranking Tie and Col Rank functions
Recode	can be very slow in combination with other options	apply the option in a second step	Recode - Parse as Number
replace values with other values	for loop or Recode	use DataTable subscripting	Replace missing values with 0 Should you Loop through a data table or use Recode, or use Get Rows Where to change values in a data...
select rows based on a formula	If dt << select where() is too slow ... split it into 2 steps:	myrows= dt << get rows where(); dt << select rows(myrows)	Formula to check if any of a list of items is contained in the rows of a column
spec calcualations	some manual JSL code	support this wish with a Kudo:	🙏 is in spec (value)
Graphs
Reports
Export
Database access
Neural Networks
...

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[#2]

It depends a lot on what you are doing. Some good general tips can be found from Scripting Guide > Efficient Scripts 

[#3]

Thanks, a good place to start ...

Going further, how about a list with as many entries as possible along the idea:
If you want to do this, you probably thought of this approach - but concerning speed, the other approach is much better!

Who is interested in sharing his secrets

[#4 · Accepted solution]

-> Table moved to main post.

[#5]

I added a cool trick to count words by @ian_jmp :
Count number of occurrences of specific words in a string 

[#6]

great source of Tips and Tricks:

JSL Scripters Club Meetings: 2024 schedule, 2023 complete list with links to recordings. 

[#7]

Wonderful talk on XPath & Subscripting in Reports:
 https://community.jmp.com/t5/Abstracts/I-Can-See-It-How-Do-I-Get-It/ev-p/776041 

[#8]

JM 19:

column aggregation with restrictions	with a character comparison Col(if(... gets very (!!!) slow: col Max( if(:sex=="M", ...)	a) use if(:sex==1,...)	How-do-I-use-the-Col-Maximum-Formula-with-a-where   (fixed in V19)
rank unique	New Column( "rank_unique", Formula( Col Minimum( Col Rank( If( Row() == Col Min( Row(), :age, :sex ), 1 ), :age ), :age,:sex))	Col Score(:age, :sex) (v19)	Add dense ranking to Ranking Tie and Col Rank functions