Krupali: Created page with '{| border=1 !Timing !Narration |- |0:02 | Hello friends and welcome to the tutorial on 'Using SAGE to teach'. |- | 0:07 | At the end of this tutorial, you will be able to, # U…'

2013-10-28T06:42:31Z

Created page with '{| border=1 !Timing !Narration |- |0:02 | Hello friends and welcome to the tutorial on 'Using SAGE to teach'. |- | 0:07 | At the end of this tutorial, you will be able to, # U…'

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{| border=1
!Timing
!Narration
|-
|0:02
| Hello friends and welcome to the tutorial on 'Using SAGE to teach'.

|-
| 0:07
| At the end of this tutorial, you will be able to,

# Use @interact feature of SAGE for better demonstration.
# Share, publish and edit SAGE worksheets for collaborative learning.

|-
| 0:19
| Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with Sage" and "Getting started with Symbolics."

|-
| 0:30
| Let us start by looking at a typical example of demonstrating a damped oscillation.

|-
|0:40
|So you can type t=var('t') ,then next line you can type p1=plot (e raised to minus (-t)into sin of (2 into t),(t,0,15))

|-
|1:06
|then third line you can type show(p1)

|-
| 1:17
| Now let us reduce the damping factor by half

|-
|1:23
|so for that you have to type t=var('t')

|-
|1:33
|then p1=plot(e raised to (-t by 2) * sin(2 into t),(t,0,15))

|-
|1:48
|then third line you can type show(p1)

|-
| 1:53
| Now, if we want to reduce the damping factor even more, we would be using e charat to (-t by 3).

|-
|2:04
| We can observe that every time we have to change, all we do is change something very small and re-evaluate the cell.

|-
|2:10
|This process can be simplified, using the @interact feature of SAGE.

|-
|2:17
|So you can type @interact ,then def plot_damped(n-1):

|-
|2:32
|Then, t=var('t')

|-
|2:49
|p1=plot (e raised to(-t/n) * sin(2*t),(t,0,20))

|-
|3:01
|then type show(p1)

|-
| 3:11
| We can see that the function is evaluated and the plot is shown.

|-
|3:15
| We can also see that there is a field to enter the value of n and it is currently set to 1 .

|-
|3:21
| Let us change it to 2 and hit enter.

|-
|3:23
|So you type 2 and hit enter.

|-
| 3:29
| We see that the new plot with reduced damping factor is shown.

|-
| 3:33
| Similarly we can change n to any desired value and hit enter and the function will be evaluated.

|-
|3:41
|This is a very handy tool while demonstrating or teaching.

|-
|3:45
|Pause the video here, try out the following exercise and resume the video.

|-
| 3:50
| '''Plot the sine curve and vary its frequency using the @interact'' feature.

|-
| 3:57
| Now, switch to your worksheet for solution.

|-
|4:03
|You can type @interact

|-
|4:08
|then def sine_plot(n=1):

|-
|4:12
|then x=var('x')

|-
|4:18
|then p2=plot (sin(n*x),(x,0,2*pi))

|-
|4:27
|then finally you can type show(p2)

|-
|4:43
|So often we would want to vary a parameter over range instead of taking it as an input from the user.

|-
| 4:51
| For instance we would not want the user to give n as 0 for the damping oscillation we discussed.

|-
|4:56
| In such cases we use a range of values as the default argument.

|-
|5:02
|at the rate interact

|-
|5:10
|should be typed in the worksheet so in the worksheet you can type

|-
|5:14
|@interact then def plot underscore damped(n=(1..10)):

|-
|5:28
|then next line you can type t=var('t')

|-
|5:36
|then p1=plot(e raised to (-t/n) * sin(2*t)),(t,0,20))

|-
|5:52
|then you can type show(p1)

|-
|6:08
|Now we had seen an error

|-
|6:12
|So the error that we have rectified is after sin(2*t) we have accidentally placed an extra bracket.

|-
| 6:25
| So we get similar plot but the only difference is the input widget.

|-
|6:30
| Here it is a slider unlike an input field.

|-
| 6:35
| We can see that the slider is moved, the function is evaluated and plotted accordingly.

|-
|6:48
|Pause the video here,and try out the following exercise and resume the video.

|-
| 6:52
| '''Take a string as input from user and circular shift it to the left and''' vary the shift length using a slider.

|-
| 7:03
| For this problem, again we will use the @interact feature of sage.

|-
|7:09
|We shall first assign a string say 'MADAM' to a variable and then shift the alphabets one by one.

|-
|7:17
|So we can type @interact

|-
|7:21
|def str_shift(s="MADAM", shift=(0..8)) colon

|-
|7:33
|then you can type shift_len=shift modulus len(s)

|-
|7:40
|then chars=list(s)

|-
|7:46
|then shifted_chars=chars[shift_len:]+chars[: shift_len]

|-
|8:03
|then print "Actual String:",s

|-
|8:11
|then print "Shifted String:", "".join(shifted_chars)

|-
| 8:28
| As we move the slider, we see that shifting is taking place.

|-
| 8:40
| Sometimes we want the user to have only a given set of options.

|-
| 8:44
| We use a list of items as the default argument in such situations.

|-
|8:50
|So we can type @interact

|-
|8:57
|then def str_shift(s="STRING",shift=(0..8), direction=["Left","Right"]):

|-
|9:10
|then next line shift_len=shift modulus len(s)

|-
|9:24
|then chars=list(s)

|-
|9:26
|if direction=="Right" colon

|-
|9:32
|then shifted_chars=chars[-shift_len colon]+chars[colon -shift_len]

|-
|10:01
|else colon shifted_chars=chars[shift_len colon]+chars[colon shift_len]

|-
|10:26
|then type print "Actual String:",s

|-
|10:32
|then print "Shifted String:", ""

|-
|10:52
|then dot join(shifted_chars)

|-
| 11:01
| We can see that buttons are displayed which enables us to select from a given set of options.

|-
| 11:11
| We see that, as we select left or right button, the shifting takes place appropriately.

|-
|11:18
|Thus, we have learnt how to use the @interact feature of SAGE for better demonstration.

|-
| 11:24
| Now we shall look at how to use SAGE worksheets for collaborative learning.

|-
| 11:30
| The first feature we shall see is the publish feature.

|-
|11:34
| Open a worksheet and in the top right, we can see a button called publish
|-
|11:40
|Click on that and we get a confirmation page with an option for re-publishing.

|-
|11:52
| For now lets forget that option and simply publish by clicking yes .

|-
|11:58
|The worksheet is now published.

|-
|11:59
|Now lets sign out and go to the sage notebook home.

|-
|12:04
|We see link to browse published worksheets.

|-
|12:08
| Lets click on it and we can see the worksheet.

|-
|12:12
| This does not require login and anyone can view the worksheet.

|-
|12:17
|Alternatively, if one wants to edit the sheet, there is a link on top left corner that enables the user to download a copy of the sheet onto their home.

|-
|12:36
|This way they can edit a copy of the worksheet.

|-
|12:41
|We have learnt how to publish the worksheets to enable users to edit a copy.

|-
|12:45
|Next, we shall look at how to enable users to edit the actual worksheet itself.

|-
| 12:51
| Let us open the worksheet and we see a link called share on the top right corner of the worksheet.

|-
|13:03
|Click the link and we get a box where we can type the usernames of users whom we want to share the worksheet with.

|-
|13:10
| We can even specify multiple users by separating their names using commas.

|-
|13:15
| Once we have shared the worksheet, the worksheet appears on the home of shared users.

|-
|13:22
| This brings us to the end of this tutorial.

|-
|13:24
|In this tutorial, we have learnt to,

|-
|13:25
| Use interactive features of SAGE using @interact .

|-
|13:30
| then publishing our work.

|-
|13:32
|then edit a copy of one of the published worksheets.

|-
|13:35
|then share the worksheets with fellow users.

|-
| 13:39
| Here are some self assessment questions for you to solve

|-
|13:44
|1. Which default argument, when used with @interact gives a slider starting at 0 and ending in 10.

|-
|13:52
| options are (0..11)

|-
|13:54
| then range(0, 11)

|-
|13:55
|Then [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] separated by comma

|-
|14:01
| then in brackets (0..10)

|-
|14:05
|2. What is the input widget resulted by using n = [2, 4, 5, 9]\ in the default arguments along with @interact.

|-
|14:23
| options are input field, set of buttons, slider, None

|-
| 14:29
| Now we will look at the answers,

|-
|14:31
|1.The default argument, used with @interact which gives a slider starting at 0 and ending in 10 is (0..10).

|-
|14:42
|2. The input widget resulted by using n = [2, 4, 5, 9] in the default arguments along with @interact will be a set of buttons that is the second one.

|-
| 14:57
| Hope you have enjoyed this tutorial and found it useful.

|-
|15:01
|Thank you!

|}

Python/C2/Using-sage-to-teach/Gujarati - Revision history

Krupali: Created page with '{| border=1 !Timing !Narration |- |0:02 | Hello friends and welcome to the tutorial on 'Using SAGE to teach'. |- | 0:07 | At the end of this tutorial, you will be able to, # U…'