Making knitr run a r script: do I use read_chunk or source?

Question

I am running R version 2.15.3 with RStudio version 0.97.312. I have one script that reads my data from various sources and creates several data.tables. I then have another r script which uses the data.tables created in the first script. I wanted to turn the second script into a R markdown script so that the results of analysis can be outputted as a report.

I do not know the purpose of read_chunk, as opposed to source. My read_chunk is not working, but source is working. With either instance I do not get to see the objects in my workspace panel of RStudio.

Please explain the difference between read_chunk and source? Why would I use one or the other? Why will my .Rmd script not work

Here is ridiculously simplified sample

It does not work. I get the following message

Error: object 'z' not found

Two simple files...

test of source to rmd.R

x <- 1:10 y <- 3:4 z <- x*y   

testing source.Rmd

Can I run another script from Rmd ========================================================  Testing if I can run "test of source to rmd.R"  ```{r first part} require(knitr) read_chunk("test of source to rmd.R") a <- z-1000 a ```  The above worked only if I replaced "read_chunk" with "source". I  can use the vectors outside of the code chunk as in inline usage.  So here I will tell you that the first number is `r a[1]`. The most  interesting thing is that I cannot see the variables in RStudio  workspace but it must be there somewhere. 

Answer 1

read_chunk() only reads the source code (for future references); it does not evaluate code like source(). The purpose of read_chunk() was explained in this page as well as the manual.