[R-meta] Importing Correlations from PDF to table format

[Viechtbauer, Wolfgang (SP)]

Hi Kiet,

The rcalc() function from metafor could be used for this. It even computes the var-cov matrix of the elements in the correlation matrix for you:

library(metafor)
R <- matrix(c(1, .3, .5, .3, 1, .6, .5, .4, 1), 3, 3)
R
rcalc(R, ni=50)

Best,
Wolfgang

>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>Behalf Of Kiet Huynh
>Sent: Monday, 28 February, 2022 19:45
>To: James Pustejovsky
>Cc: R meta
>Subject: Re: [R-meta] Importing Correlations from PDF to table format
>
>Hi James,
>
>Thank you for recommending these helpful packages. I was able to import the pdf
>correlation table into a dataframe format in R. Are you aware of any R code that
>could convert that correlation matrix dataframe into a meta-analysis type
>dataframe (i.e., a column for variable 1, a column for variable 2, and a column
>for correlation effect size)?
>
>Best,
>
>Kiet
>
>> On Feb 25, 2022, at 10:58 AM, James Pustejovsky <jepusto using gmail.com> wrote:
>>
>> The pdftools package might be helpful:
>> https://github.com/ropensci/pdftools <https://github.com/ropensci/pdftools>
>> It has very low-level utilities for extracting text from pdf. You'd still have
>to do some data clean-up to get the correlations into the form needed for
>analysis.
>>
>> The tabulizer package is meant to provide tools customized for working with pdf
>tables:
>> https://github.com/ropensci/tabulizer <https://github.com/ropensci/tabulizer>
>> But it requires Java and it appears to be archived on CRAN. I'm not sure what
>its development status is. Caveat emptor, I guess.
>>
>> James
>>
>> On Fri, Feb 25, 2022 at 12:20 PM Kiet Huynh <kietduchuynh using gmail.com
><mailto:kietduchuynh using gmail.com>> wrote:
>> Hello,
>>
>> I was wondering if anyone knows of a way to automate in R (or any software) the
>process of importing correlation values from PDF to usable data in a table format
>that can be used in meta-analysis? My process has been to copy the correlations
>manually one-by-one from the PDF to excel (which takes a lifetime!), and then
>import the excel data into R. I'm sure there must be a better, faster, and less
>error-prone way to do this.
>>
>> Thank you,
>>
>> Kiet
>>
>> ----
>>
>> Kiet D. Huynh, Ph.D.
>> Pronouns: he/him
>> CLEAR Goldblum-Carr Postdoctoral Fellow
>> Palo Alto University
>> 1791 Arastradero Rd.
>> Palo Alto, CA 94304