topic Re: Turning a continuous variable into a discrete variable in Discussions

Turning a continuous variable into a discrete variable

dannyfinn11 — Sun, 10 Jun 2018 17:06:39 GMT

Hi all - was wondering if someone could give me a few pointers on a problem I'm struggling with. I would like to create a dummy variable using a range of values based on a continuous variable.

I would like to take a set of values and place them in nominal "buckets" if you will.

For example the data is

I want take those values and id when range they fall into. So 1- 12, 13-20, etc. Any ideas??

Re: Turning a continuous variable into a discrete variable

txnelson — Sun, 10 Jun 2018 19:53:32 GMT

select the column you are interested in, and then go to

Cols==>Recode

and create a new column that has the values binned into new groups

Re: Turning a continuous variable into a discrete variable

dannyfinn11 — Sun, 10 Jun 2018 20:19:21 GMT

done. But what about large datasets? The one I was working on was only 450 rows. If I have a dataset with 29K rows, can I use a formula to go through and recode everything?

Re: Turning a continuous variable into a discrete variable

txnelson — Mon, 11 Jun 2018 00:04:16 GMT

1. Yes you can use a formula. Here is one version that you could use

If( Row() == 1,
	min = Col Min( :height );
	incr = (Col Max( :height ) - Col Min( :height )) / 9;
);
Floor( (:height - min) / incr ) + 1;

It uses the Big Class sample data table. Just change the variable :Height out for the column you are calculating against.

2. But the number of rows does not affect the Recode. Only the number of unique values within those rows.

Re: Turning a continuous variable into a discrete variable

Mark_Bailey — Mon, 11 Jun 2018 13:41:53 GMT

I think that Jim already answered your question, but I wanted to expand a bit on the answer. The If() function in a formula or script is very versatile. Here is an example of what you want to do (bin data) from our JMP Software: Introduction to the JMP Scripting Language:

It compares the numeric value in Age with the cutoffs and returns a character string in the new column, Stage.

Re: Turning a continuous variable into a discrete variable

Mark_Bailey — Mon, 11 Jun 2018 13:44:47 GMT

I forgot to mention that if you are not otherwise scripting, you can interactively create a new data column with the bins: select the data column with the continuous values and then select Cols > Utilities > Make Binning Formula.

Re: Turning a continuous variable into a discrete variable

dannyfinn11 — Mon, 11 Jun 2018 13:52:10 GMT

YES!! This is what I needed :) Thank you!!

Re: Turning a continuous variable into a discrete variable

Jeff_Perkinson — Mon, 11 Jun 2018 14:13:55 GMT

You may find the Interactive Binning add-in useful.

Re: Turning a continuous variable into a discrete variable

JSpear — Sun, 12 Jul 2020 00:29:09 GMT

I tried to follow this example using a column formula. I get no error but the column is blank.

Re: Turning a continuous variable into a discrete variable

Craige_Hales — Sun, 12 Jul 2020 02:53:34 GMT

if "Pilot A", etc, is a string, it needs quotation marks. There might be a message in the log about an undefined variable.