Question

Question 5

0/1 point (graded)

The following is the full path to a homework assignment file called "assignment.txt": /Users/student/Documents/projects/homeworks/assignment.txt.

Which line of code will allow you to move the assignment.txt file from the “homeworks” directory into the parent directory “projects”?

mv assignment.txt

mv assignment.txt .

mv assignment.txt ..

mv assignment.txt /projects incorrect

Answer

Incorrect:

Try again. This code does not provide enough information about where to move the file. You need to specify a relative or full path to the location where you want to move the file to.

Question 9

0/1 point (graded)

The source function reads a script from a url or file and evaluates it. Check ?source in the R console for more information.

Suppose you have an R script at ~/myproject/R/plotfig.R and getwd() shows ~/myproject/result, and you are running your R script with source('~/myproject/R/plotfig.R').

Which R function should you write in plotfig.R in order to correctly produce a plot in ~/myproject/result/fig/barplot.png?

ggsave('fig/barplot.png'), because this is the relative path to the current working directory.

ggsave('../result/fig/barplot.png'), because this is the relative path to the source file ("plotfig.R"). incorrect

ggsave('result/fig/barplot.png'), because this is the relative path to the project directory.

ggsave('barplot.png'), because this is the file name.

Question 12

1 point possible (graded)

Which of the following meanings for options following less are not correct?

(Hint: use man less to check.)

-g: Highlights current match of any searched string

-i: case-insensitive searches

-S: automatically save the search object

-X: leave file contents on screen when less exits.

Question 13

1 point possible (graded)

Which of the following statements is incorrect about preparation for a data science project?

Select ALL that apply.

Always use absolute paths when working on a data science project.

Saving .RData every time you exit R will keep your collaborator informed of what you did.

Use ggsave to save generated files for use in a presentation or a report.

Saving your code in a Word file and inserting output images is a good idea for making a reproducible report.

Answer 1

Question 5

The following is the full path to a homework assignment file called "assignment.txt": /Users/student/Documents/projects/homeworks/assignment.txt.

Which line of code will allow you to move the assignment.txt file from the “homeworks” directory into the parent directory “projects”?

mv assignment.txt

mv assignment.txt .

mv assignment.txt ..

mv assignment.txt /projects

Answer : mv assignment.txt ..

syntax to move file is : mv filename directoryPath

To denote parent directory we use ".." (double dots) in unix. Hence in the above question it is  mv assignment.txt ..

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Question 9

The source function reads a script from a url or file and evaluates it. Check ?source in the R console for more information.

Suppose you have an R script at ~/myproject/R/plotfig.R and getwd() shows ~/myproject/result, and you are running your R script with source('~/myproject/R/plotfig.R').

Which R function should you write in plotfig.R in order to correctly produce a plot in ~/myproject/result/fig/barplot.png?

Answer : ggsave('fig/barplot.png'), because this is the relative path to the current working directory.

While executing the script , it takes current working directory which is "~/myproject/result" . Hence to save the plot in ~/myproject/result/fig/barplot.png, have to use fig/barplot.png.

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Question 12

Which of the following meanings for options following less are not correct?

(Hint: use man less to check.)

Answer : -S: automatically save the search object

-g: Highlights current match of any searched string ->correct

-i: case-insensitive searches ->correct

-S: automatically save the search object ->incorrect (-S means Chop (truncate) long lines rather than wrapping.)

-X: leave file contents on screen when less exits. ->correct

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Question 13

Which of the following statements is incorrect about preparation for a data science project?

Select ALL that apply.

Answer :

Always use absolute paths when working on a data science project. ->(You should never use absolute paths in your scripts, because they hinder sharing: no one else will have exactly the same directory configuration as you.)