wiki/debug.line.md

In ProvTools/provDebugR: A Time-Travelling Debugger

For each line number queried, debug.line returns a data frame of the data that the procedure in that line inputs and outputs.

Each data frame contains the following columns: name The name of the data. value The value of the data. container The type of the container of the data. dimension The size of the container. * type The data type(s) contained within the container.

Usage

The function signature for debug.line is:

debug.line(..., script.num = 1, all = FALSE)

The parameters of this function are: ... The line numbers to be queried script.num The script numbers to be queried. Defaults to script number 1 (main script). If script.num == "all", all possible script numbers will be queried. * all If TRUE, the inputs and outputs for all lines in all script numbers will be returned.

In the case of multiple queries, only 1 script number may be queried per function call.

This function may be called only after initialising the debugger using either prov.debug, prov.debug.run, or prov.debug.file. For example:

prov.debug.run("myScript.R")
debug.line(5)
debug.line(all = TRUE)
debug.line(5, 10, script.num = 2)
debug.line(3, script.num = "all")

Output Examples

Let myScript.R be the following:

x <- 1:3
y <- c("a", "b", "c")
xy <- data.frame(x, y, stringsAsFactors = FALSE)
x

1. The line has both inputs and output data nodes

The result for debug.line(3) is:

Results for:
  startLine scriptNum scriptName                                             code
1         3         1 myScript.R xy <- data.frame(x, y, stringsAsFactors = FALSE)

$`1`
$`1`$input
  name       value container dimension      type
1    x       1 2 3    vector         3   integer
2    y "a" "b" "c"    vector         3 character

$`1`$output
  name     value  container dimension               type
1   xy Row 1 1 a data_frame       3,2 integer, character

Variables x and y are listed in the 'input' table as they are used in the procedure.

Variable xy is listed in the 'output' as the result from the procedure is assigned to that variable.

2. The line has either inputs or outputs

If the line has only inputs or outputs, an NA will be put in the place of the data frame with no data nodes listed.

Line 1 has no inputs, so the result for debug.line(1) is:

Results for:
  startLine scriptNum scriptName      code
1         1         1 myScript.R x <- 1:3

$`1`
$`1`$input
[1] NA

$`1`$output
  name value container dimension    type
1    x 1 2 3    vector         3 integer

Line 4 has no outputs, so the result for debug.line(4) is:

Results for:
  startLine scriptNum scriptName code
1         4         1 myScript.R    x

$`1`
$`1`$input
  name value container dimension    type
1    x 1 2 3    vector         3 integer

$`1`$output
[1] NA

3. Results for multiple line queries

If multiple lines are queried, the results for each line will be bound into a list. The resulting data structure is a list of lists of 2 data frames.

For example, the result for debug.line(1,3,4) is:

Results for:
  startLine scriptNum scriptName                                             code
1         1         1 myScript.R                                         x <- 1:3
2         3         1 myScript.R xy <- data.frame(x, y, stringsAsFactors = FALSE)
3         4         1 myScript.R                                                x

$`1`
$`1`$input
[1] NA

$`1`$output
  name value container dimension    type
1    x 1 2 3    vector         3 integer


$`2`
$`2`$input
  name       value container dimension      type
1    x       1 2 3    vector         3   integer
2    y "a" "b" "c"    vector         3 character

$`2`$output
  name     value  container dimension               type
1   xy Row 1 1 a data_frame       3,2 integer, character


$`3`
$`3`$input
  name value container dimension    type
1    x 1 2 3    vector         3 integer

$`3`$output
[1] NA

ProvTools/provDebugR documentation built on April 29, 2021, 7:22 p.m.