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09-11-2016 09:38 PM - edited 09-11-2016 10:23 PM

Hi,

I have a data with over 20 variables and over a 100 rows of data.

For each variable I would like to create a dummy variable which depends on the median of the values of that variable. Here is an example to illustrate:

I have a column named "age" containing ages. I would like to calculate the median age, and suppose it equals 29, so if for an entry the value for age is greater than the median, say 35, then the new variable "age_dummy" will be equal to 1, and if age is less than or equal to the median, like 25, than the dummy will be equal to 0.

so if the initial data is something like this:

age |

25 |

29 |

31 |

35 |

Then I would like the final data to be of the following:

age | age_dummy |

25 | 0 |

29 | 0 |

31 | 1 |

35 | 1 |

Thank you!

Accepted Solutions

Solution

09-11-2016
11:59 PM

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09-11-2016 10:25 PM - edited 09-11-2016 10:27 PM

Use the RANK procedure

```
proc rank data=have out=want groups=2;
var var1-var20;
ranks rvar1-rvar20;
run;
```

Below and above median will be identified with group number 0 and 1, respectively.

PG

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09-11-2016 09:51 PM

So which part is your question?

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09-11-2016 10:12 PM

Hi Reeza,

for each column I would like to calculate the median of the numbers, and then for each colum create a new column which will consist of dummy values (0 or 1). So basically there are 2 subquestions: calculating the median of a column and creating a new column of dummy variables.

Thanks!

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09-11-2016 10:23 PM

Here I would like to add some illustration:

suppose the initial data is something like this:

age |

25 |

29 |

31 |

35 |

Then I would like the final data to be of the following:

age | age_dummy |

25 | 0 |

29 | 0 |

31 | 1 |

35 | 1 |

And please note that I have over 20 variables so if possible to make the entire process automatic for all the variables.

Thanks!

Solution

09-11-2016
11:59 PM

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09-11-2016 10:25 PM - edited 09-11-2016 10:27 PM

Use the RANK procedure

```
proc rank data=have out=want groups=2;
var var1-var20;
ranks rvar1-rvar20;
run;
```

Below and above median will be identified with group number 0 and 1, respectively.

PG

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09-11-2016 11:00 PM

Hi PGStats,

thank you for the reply, I clearly got the dummy values depending on the median.

now I get the dummy columns but the original columsn disappear, and I need the original columns and I can't just merge becasue both the original columns and their corresponding new dummy columns have the same name.

Thanks!

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09-11-2016 11:23 PM

If you used the RANK statement that's not what should have happened.

Please post your code.

Also verify that the variable name and labels are different.

http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/viewer.htm#a002473611.htm

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09-11-2016 11:58 PM

That's good now I realized that I forgot to put the "r" before the original varible name

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09-11-2016 11:23 PM

Dataset **want** should contain original variables (**var1-var20**) __and__ new variables** rvar1-rvar20**, just as you need. I would need to see your log to understand what happened.

PG

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09-11-2016 11:58 PM

That's good now I realized that I forgot to put the "r" before the original varible name!

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09-12-2016 12:20 PM

I posted what I think is a more comprehensive 'R' based solution. This solution should map easly to IML.

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09-12-2016 10:08 PM

Hi rogerjdeangelis,

I would love to see the solution, but when I clicked on the link I was asked for a password, so is there another way of accessing your solution?

Thnak you!