2017-01-11.sagews

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# Math 152: Intro to Mathematical Software
### 2017-01-11
### Kiran Kedlaya; University of California, San Diego
### adapted from lectures by William Stein, University of Washington

## **Lecture 2: Introduction to SageMathCloud**

Math 152: Intro to Mathematical Software

2017-01-11

Kiran Kedlaya; University of California, San Diego

adapted from lectures by William Stein, University of Washington

Lecture 2: Introduction to SageMathCloud

Goal

Today will be a tour of how to use SageMathCloud (SMC).

Some things that SMC can do (not a complete list)

• SageMath: command line, run programs, use worksheets

• Python

• R

• Latex

• Jupyter notebooks

• Terminal

• Edit files and compile/run code (e.g., Java, C/C++, Fortran, etc.)

• To-do lists

• Chat rooms (for collaboration), including video

Also, course management

• So your other professors can use SMC in their courses

Rest of today

Tutorial -- Follow along on your laptop!

At this point, you should have created an account with SMC and found the "master" and "shared" projects associated to the course.

From the projects view (click "projects" to get there), open your master project.

Then click "files", then "assignments", then "2017-01-11", then "2017-01-11.sagews".

You should now have in front of you a copy of this worksheet.

This copy is yours; you may make whatever changes you want without worrying about clobbering anyone else's changes (or my original copy).

All changes to worksheets are reversible; click the TimeTravel button to see a view of all past changes (pull the slider to move through time).

Now let's see how to interact with Sage worksheets, such as this one.

Click on the empty space immediately below this box.

Pick your favorite two positive integers, say 3 and 5. Type "3+5" and hit Shift-Enter to evaluate the expression. (Note that expressions can run over multiple lines, so hitting Enter inserts a line break instead of evaluating.)

Then change one of the values and evaluate again.

15+37

52

Sage can do much more interesting things than this! Try playing with the following example.

%var x y z
g = golden_ratio; r = 5.77
p = 2.5 - (sin(x + g*y) + sin(x - g*y) + sin(y + g*z) +
         sin(y - g*z) + sin(z - g*x) + sin(z + g*x))
show(implicit_plot3d(p, (x, -r, r), (y, -r, r), (z, -r, r),
                plot_points=30, color='blue', mesh=.5, opacity=.5), spin=1)

3D rendering not yet implemented

When you are editing the worksheet, you can insert more examples by clicking on the buttons labeled "Plots", "Calculus", etc.

Things to do for the rest of the lecture:

• Create a folder named scratch

• Add another student from the course to your project (settings --> add collab); you can remove them at any time.

• Create various types of files in that folder (you don't need to know what these do yet)

  • A .txt file (type a little and inspect "TimeTravel")

  • A .md file

  • A .html file

  • A sage worksheet

  • A jupyter notebook

  • A todo list

  • A chatroom

  • A terminal

  • A latex document

  • Upload a file from your computer (+New)

• Look at the "Log"

• Look at Backups

• Use Find to search in files

• Stop/Save/Restart your project (in project settings)

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