In the 39th session of Chandoo.org podcast, Let’s learn about FOR loops.
There is a special giveaway in this podcast. It is a workbook with several FOR loop VBA code examples. Listen to the episode for instructions.
What is in this session?
In this podcast,
- Announcements
- What is a loop – plain English & technical definitions
- For Loop vs. other kind of loops (While & Until)
- For Next loops
- For Each loops
- Nested For loops
- Special tips on For loops
- Performance issues & infinite loops
- Conclusions & giveaway
Listen to this session
Podcast: Play in new window | Download
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Click here to download the MP3 file.
Links & Resources mentioned in this podcast
Introduction to VBA
- Introduction to Excel VBA – 5 part crash course
- Introduction to VBA – what is it and how to get started – Podcast #22
Using FOR Loops – Examples
- Looking up when data wont play nice – Using FOR Loops
- Understanding variables, conditions & loops in VBA
- Split an Excel file in to many using For Each loop
Optimization & Performance of VBA code
Transcript of this session:
Download this podcast transcript [PDF]
Are FOR loops strong with your VBA code?
I personally favor FOR loops over While loops. I learned about loops in 1996 (in BASIC language). Any powerful application or program I have built ever since has its share of FOR loops. They are vital for doing awesome things with computers.
What about you? Do you use FOR loops often? When do you use them? What are your favorite implementations. Please share your tips & thoughts in the comments area.
Remember: Email me at chandoo.d@gmail.com once you finish the task mentioned in the podcast to get your FOR loops example workbook.
8 Responses to “Pivot Tables from large data-sets – 5 examples”
Do you have links to any sites that can provide free, large, test data sets. Both large in diversity and large in total number of rows.
Good question Ron. I suggest checking out kaggle.com, data.world or create your own with randbetween(). You can also get a complex business data-set from Microsoft Power BI website. It is contoso retail data.
Hi Chandoo,
I work with large data sets all the time (80-200MB files with 100Ks of rows and 20-40 columns) and I've taken a few steps to reduce the size (20-60MB) so they can better shared and work more quickly. These steps include: creating custom calculations in the pivot instead of having additional data columns, deleting the data tab and saving as an xlsb. I've even tried indexmatch instead of vlookup--although I'm not sure that saved much. Are there any other tricks to further reduce the file size? thanks, Steve
Hi Steve,
Good tips on how to reduce the file size and / or process time. Another thing I would definitely try is to use Data Model to load the data rather than keep it in the file. You would be,
1. connect to source data file thru Power Query
2. filter away any columns / rows that are not needed
3. load the data to model
4. make pivots from it
This would reduce the file size while providing all the answers you need.
Give it a try. See this video for some help - https://www.youtube.com/watch?v=5u7bpysO3FQ
Normally when Excel processes data it utilizes all four cores on a processor. Is it true that Excel reduces to only using two cores When calculating tables? Same issue if there were two cores present, it would reduce to one in a table?
I ask because, I have personally noticed when i use tables the data is much slower than if I would have filtered it. I like tables for obvious reasons when working with datasets. Is this true.
John:
I don't know if it is true that Excel Table processing only uses 2 threads/cores, but it is entirely possible. The program has to be enabled to handle multiple parallel threads. Excel Lists/Tables were added long ago, at a time when 2 processes was a reasonable upper limit. And, it could be that there simply is no way to program table processing to use more than 2 threads at a time...
When I've got a large data set, I will set my Excel priority to High thru Task Manager to allow it to use more available processing. Never use RealTime priority or you're completely locked up until Excel finishes.
That is a good tip Jen...