JS as a teaching language

[Ben Crowell]

I teach physics at a community college, and ca. 2000 I experimented
with using python as a teaching tool. The point wasn't to teach
programming per se, but simply to give students a way of solving
problems numerically when there isn't any way to get a closed-form
solution using algebra or calculus. Other physics teachers have done
similar things using spreadsheets, but personally I think that's
a horrendous approach -- partly because spreadsheets aren't
standardized the way programming languages are, and partly because
spreadsheets aren't readable in the way that code is. I think my
experiment was partly successful and partly unsuccessful. I'm now
about to teach the same course again for the first time in a long
time, and am thinking about the possible merits of switching from
python to javascript. I'd be grateful for comments from anyone on
whether this seems like a good idea, or on certain aspects of what
I'm thinking of doing.

One hurdle I encountered with python was that I had to make sure
my students had access to a python interpreter. This meant downloading
a large application and installing it. This seems like a clear win
for js, since everyone who has firefox installed can run one-liners
in the console, and I would think it would be fairly straightforward
to supply a browser-based interface that would allow the user to
write simple javascript programs and run them.

It was also a nuisance in python that a computation as simple as
taking the square root of 2 required this much code:
import math
print math.sqrt(2.)
Also, it confused students that
print 2/3
gave 0 as its output. I found that many students were confused by
the significance of whitespace in python.

None of this was an insurmountable hurdle, but it
took up time and got in the way. (I remember in particular one
student, a middle-aged immigrant, who not only had never done any
computer programming, but didn't know how to hold a mouse.)

In js, the first example above becomes simpler:
Math.sqrt(2) ,
and the second one works as one naively expects.

I'm also thinking about the idea of making things a little easier
on the students by exposing some globals. For example, their own
code could run in an environment where the following has already
been done:
sqrt=Math.sqrt;
Thus they can simply do
sqrt(2)
and get an answer.

Are there any well-implemented, open-source, browser-based environments
for writing simple javascript programs? I would want to incorporate
such a thing as a component in some open-source courseware I've
written (http://www.lightandmatter.com/spotter/spotter.html), probably
using some ajaxy method for allowing the user to save his programs
on my server.

Thanks in advance for any advice or comments!

-Ben

[McKirahan]

"Ben Crowell" <cr*******@ligh tSPAMandISmatte rEVIL.comwrote in message
news:47******** *************** @roadrunner.com ...

I teach physics at a community college, and ca. 2000 I experimented
with using python as a teaching tool. The point wasn't to teach
programming per se, but simply to give students a way of solving
problems numerically when there isn't any way to get a closed-form
solution using algebra or calculus. Other physics teachers have done
similar things using spreadsheets, but personally I think that's
a horrendous approach -- partly because spreadsheets aren't
standardized the way programming languages are, and partly because
spreadsheets aren't readable in the way that code is. I think my
experiment was partly successful and partly unsuccessful. I'm now
about to teach the same course again for the first time in a long
time, and am thinking about the possible merits of switching from
python to javascript. I'd be grateful for comments from anyone on
whether this seems like a good idea, or on certain aspects of what
I'm thinking of doing.

One hurdle I encountered with python was that I had to make sure
my students had access to a python interpreter. This meant downloading
a large application and installing it. This seems like a clear win
for js, since everyone who has firefox installed can run one-liners
in the console, and I would think it would be fairly straightforward
to supply a browser-based interface that would allow the user to
write simple javascript programs and run them.

It was also a nuisance in python that a computation as simple as
taking the square root of 2 required this much code:
import math
print math.sqrt(2.)
Also, it confused students that
print 2/3
gave 0 as its output. I found that many students were confused by
the significance of whitespace in python.

None of this was an insurmountable hurdle, but it
took up time and got in the way. (I remember in particular one
student, a middle-aged immigrant, who not only had never done any
computer programming, but didn't know how to hold a mouse.)

In js, the first example above becomes simpler:
Math.sqrt(2) ,
and the second one works as one naively expects.

I'm also thinking about the idea of making things a little easier
on the students by exposing some globals. For example, their own
code could run in an environment where the following has already
been done:
sqrt=Math.sqrt;
Thus they can simply do
sqrt(2)
and get an answer.

Are there any well-implemented, open-source, browser-based environments
for writing simple javascript programs? I would want to incorporate
such a thing as a component in some open-source courseware I've
written (http://www.lightandmatter.com/spotter/spotter.html), probably
using some ajaxy method for allowing the user to save his programs
on my server.

JavaScript math may be problematic:

4.7 Why does simple decimal arithmetic give strange results?

For example, 5*1.015 does not give exactly 5.075 and 0.06+0.01
does not give exactly 0.07 in javascript.

comp.lang.javas cript FAQ - 9.88 - 2007-10-12
http://jibbering.com/faq/index.html

[Andreas M.]

Am 14.10.2007 23:59 Ben Crowell wrote

I teach physics at a community college, and ca. 2000 I experimented

I ain't that much of a number-cruncher, but I got some skills in
installing software ;-)

Javascript may be more easy to grab and more freeform as Python is (I do
both), but since Python is being written by a mathematician I would
assume, that for your particulare task it may be suited better.
Should you stay with Python I would recommend you to have a look at this:

---------------------- http://ipython.scipy.org -----------------------
IPython: an Enhanced Python Shell

IPython is a multiplatform, Free Software project (BSD licensed) that
offers:

* An enhanced Python shell designed for efficient interactive work.
It includes many enhancements over the default Python shell, including
the ability for controlling interactively all major GUI toolkits in a
non-blocking manner.
* A library to build customized interactive environments using
Python as the basic language (but with the possibility of having
extended or alternate syntaxes).
* A system for interactive distributed and parallel computing (this
is part of IPython's new development).
------------------------------------------------------------------------
Basically it is an enhanced Python Shell with user definable startup
configuration and what not. Very comfortable!

I'm also thinking about the idea of making things a little easier
on the students by exposing some globals. For example, their own

This may work well with iPython (see above)

Are there any well-implemented, open-source, browser-based environments
for writing simple javascript programs? I would want to incorporate

Of course, Javascript is better suited for beginners, especially since
it is less loaded. One can lose overview with Python pretty fast.

Check these out:

http://jconsole.com/
or
http://mochikit.com/examples/interpreter/index.html

Good luck!

--
Regards,
Andreas M.

[Andreas M.]

Am 15.10.2007 01:03 McKirahan wrote

Perhaps you could use Internet Explorer with VBScript...

Type the following in the Address bar and hit Enter:
vbscript:Alert( 5*1.015 )
or
vbscript:Alert( 2^.5 )

or
jscript:Alert( 5*1.015 )
or
jscript:Alert( 2^.5 )

;-)

--
Greetings,
Andreas M.

[Richard Cornford]

Ben Crowell wrote:
<snip>

One thing that occurs to me that might be somewhat more of
an issue would be the lack of an exponentiation operator.
I would imagine people trying to do something like this:
2^.5 ,

Math.pow(2, 0.5); //?

and expecting the square root of two as a result.

That would be unfortunate, as the square root of 2 does not exist.

I suppose it's
not possible to overload operators in js.

Not in standard (ECMA 262 defined) javascript.

Richard.

[Ben Crowell]

Andreas M. wrote:

Check these out:

http://jconsole.com/
or
http://mochikit.com/examples/interpreter/index.html

Excellent -- that was exactly what I was looking for!
Thanks!

[Randy Webb]

Richard Cornford said the following on 10/14/2007 7:18 PM:

Ben Crowell wrote:
<snip>

>One thing that occurs to me that might be somewhat more of
an issue would be the lack of an exponentiation operator.
I would imagine people trying to do something like this:
2^.5 ,

Math.pow(2, 0.5); //?

>and expecting the square root of two as a result.

That would be unfortunate, as the square root of 2 does not exist.

It doesn't? I say it does. What doesn't exist is the potential to
display it accurately on a computer.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javas cript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Ben Crowell]

McKirahan wrote:

Perhaps you could use Internet Explorer with VBScript...

Type the following in the Address bar and hit Enter:
vbscript:Alert( 5*1.015 )
or
vbscript:Alert( 2^.5 )

I don't want to use proprietary software for this. My students
may not have access at home to proprietary software such as IE.

[Richard Cornford]

On Oct 15, 12:41 am, Randy Webb wrote:

Richard Cornford said the following on 10/14/2007 7:18 PM:

>Ben Crowell wrote:

<snip>

>>and expecting the square root of two as a result.

>That would be unfortunate, as the square root of 2
does not exist.

It doesn't? I say it does.

<snip>

No the square root of 2 does not exist. There is a reductio ad
absurdum proof that shows that if 2 has a square root then it is
necessary for there to exist a number that has magnitude but is
simultaneously positive and negative. That is impossible so 2 cannot
have a square root. Hence the square root of 2 is one of the
'imaginary' numbers.

Richard.

[David Mark]

On Oct 14, 7:58 pm, Richard Cornford <Richard.Cornf. ..@googlemail.c om>
wrote:

On Oct 15, 12:41 am, Randy Webb wrote:Richard Cornford said the following on 10/14/2007 7:18 PM:

Ben Crowell wrote:

<snip>

>and expecting the square root of two as a result.

That would be unfortunate, as the square root of 2
does not exist.

It doesn't? I say it does.

<snip>

No the square root of 2 does not exist. There is a reductio ad
absurdum proof that shows that if 2 has a square root then it is
necessary for there to exist a number that has magnitude but is
simultaneously positive and negative. That is impossible so 2 cannot
have a square root. Hence the square root of 2 is one of the
'imaginary' numbers.

I think irrational is the correct term, but it has been a while since
I cared about such things. IIRC, imaginary numbers are even roots of
negative numbers.