'Find closest datapoint to a date in another dataframe
I have two data frames. One data frame is called Measurements and has 500 rows. The columns are PatientID, Value and M_Date. The other data frame is called Patients and has 80 rows and the columns are PatientID, P_Date.
Each patient ID in Patients is unique. For each row in Patients, I want to look at the set of measurements in Measurements with the same PatientID (there are maybe 6-7 per patient).
From this set of measurements, I want to identify the one with M_Date closest to P_Date. I want to append this value to Patients in a new column. How do I do this? I tried using ddplyr but can't figure out how to access two data frames at once within this function.
Solution 1:[1]
you probably want to install the install.packages("survival") and the neardate function within it to solve your problem.
It has a good example in the documentation
Sources
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Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | e.matt |