debug.variable

For each variable queried, debug.variable returns a data frame of all instances (data nodes) of that variable.

Each data frame contains the following columns:

• value The value of the variable.
• container The type of the container of the variable.
• dimension The size of the container.
• type The data type(s) contained within the container.
• scriptNum The script number the variable is associated with.
• scriptName The name of the script the variable or file is associated with.
• startLine The line number the variable is associated with.
• code The code this variable is associated with.

Usage

The function signature for debug.variable is:

debug.variable(..., val.type = "all", script.num = "all", all = FALSE)

The parameters of this function are:

• ... The variable names to be queried.
• val.type If not "all", this filters the results to contain only instances where the valType (container or type) has the queried type.
• script.num The script number of the queried variables. Defaults to "all".
• all If TRUE, results for all variables of the specified script will be returned.

Only 1 script number and/or valType 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.variable(x)
debug.variable(all = TRUE)
debug.variable("a", b, "x", val.type = "logical")
debug.variable("a", "b", x, script.num = 3)

Output Examples

Let myScript.R be the following:

a <- "one"
a <- "two"
a <- 1L
a <- 2L

b <- 3L
b <- 4L
b <- "five"

1. Checking for all instances of a variable

The result for debug.variable("a") is:

$a
  value container dimension      type scriptNum scriptName startLine       code
1 "one"    vector         1 character         1 myScript.R         1 a <- "one"
2 "two"    vector         1 character         1 myScript.R         2 a <- "two"
3     1    vector         1   integer         1 myScript.R         3    a <- 1L
4     2    vector         1   integer         1 myScript.R         4    a <- 2L

2. Checking for all instances of a variable with a certain type

The result for debug.variable("a", val.type = "integer") is:

$a
  value container dimension    type scriptNum scriptName startLine    code
1     1    vector         1 integer         1 myScript.R         3 a <- 1L
2     2    vector         1 integer         1 myScript.R         4 a <- 2L

3. Checking for all instances of multiple variables

When multiple variables are queried, the results for each variable are bound together in a list, resulting a list of data frames.

The result for debug.variable("a","b") is:

$a
  value container dimension      type scriptNum scriptName startLine       code
1 "one"    vector         1 character         1 myScript.R         1 a <- "one"
2 "two"    vector         1 character         1 myScript.R         2 a <- "two"
3     1    vector         1   integer         1 myScript.R         3    a <- 1L
4     2    vector         1   integer         1 myScript.R         4    a <- 2L

$b
   value container dimension      type scriptNum scriptName startLine        code
1      3    vector         1   integer         1 myScript.R         6     b <- 3L
2      4    vector         1   integer         1 myScript.R         7     b <- 4L
3 "five"    vector         1 character         1 myScript.R         8 b <- "five"

4. Checking for all instances of a multiple variables with a certain type

The result for debug.variable("a", "b", val.type = "integer") is:

$a
  value container dimension    type scriptNum scriptName startLine    code
1     1    vector         1 integer         1 myScript.R         3 a <- 1L
2     2    vector         1 integer         1 myScript.R         4 a <- 2L

$b
  value container dimension    type scriptNum scriptName startLine    code
1     3    vector         1 integer         1 myScript.R         6 b <- 3L
2     4    vector         1 integer         1 myScript.R         7 b <- 4L