dale reed

The message below is being cross-posted from LogoForum.


computer users first and free),

Borland's Turbo Pascal(TP) was the first language that was used for
engineering purposes, on the new PCs(no Apples) slowly introduced into
Boeing over 15 years ago. Analysis and plotting TP programs were


programs
were created not by programmers but by engineers without any formal
computer
or programming training. On our own time, when the bosses were not
looking, especially on weekends. Eventually we started buying PC's(TP)
to
be used at home but they were mighty expensive and most
offsite(worldwide
field sites) calculations were still done with programmable HP
calculators
which replaced the sliderules we had used before.

Of course the really serious design work was done(before and after the
PC's
were introduced) on mainframes(FORTRAN batch jobs where a
misplaced/missing
comma would cause a Fatal Error resulting in reams and reams of wasted
paper.) The mainframe FORTRAN software was created by highly skilled
computer programmers(lots of them) working with a few electromagnetic
engineers who could deal with Maxwell's Equations, transmission lines,
antennas, etc. There was a PDC something or other that the most aware
engineers were modeling with but my only experience with this computer
was
using it(connected to a digitizing table and pen) to digitize the cross
section of a horizontal stabilizer for lightning current flow
calculations
on the mainframe and the PC's.

The above briefly describes my computer experiences while engineering
the
protection against the High Altitude Nuclear ElectroMagnetic Pulse(NEMP)
protection of the buried(Montana, Missouri, Wyoming, South Dakota...)
Minuteman nukes, and during my design of the Induced Lightning
shielding for
the fly-by-wire 777. Swords into Plowshares!

I have never used BASIC but I probably still have a few BASIC fractals
etc.
that Yehuda posted to this LogoForum a few years ago. My oldest son(40
year
old Professional Electrical Engineer) presently does some VISUAL BASIC
programming during his work. But once again, I assume this is done
during
spare moments and at home rather than during his normal work day. Dale
---
$ dale-reed@att.net Seattle, Washington USA $


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cheryl hughes

The message below is being cross-posted from LogoForum.

ahhhh, the days of slide-rules, where have they gone?
I have a 10-foot Picket on the wall of my high school classroom right
now. It brings back great memories.
Cheryl


home
computer users first and free),

Borland's Turbo Pascal(TP) was the first language that was used for
engineering purposes, on the new PCs(no Apples) slowly introduced into
Boeing over 15 years ago. Analysis and plotting TP programs were written
and used to design and compare calculated and measured data. These
programs
were created not by programmers but by engineers without any formal
computer
or programming training. On our own time, when the bosses were not
looking, especially on weekends. Eventually we started buying PC's(TP)
to
be used at home but they were mighty expensive and most
offsite(worldwide
field sites) calculations were still done with programmable HP
calculators
which replaced the sliderules we had used before.

Of course the really serious design work was done(before and after the
PC's
were introduced) on mainframes(FORTRAN batch jobs where a
misplaced/missing
comma would cause a Fatal Error resulting in reams and reams of wasted
paper.) The mainframe FORTRAN software was created by highly skilled
computer programmers(lots of them) working with a few electromagnetic
engineers who could deal with Maxwell's Equations, transmission lines,
antennas, etc. There was a PDC something or other that the most aware
engineers were modeling with but my only experience with this computer
was
using it(connected to a digitizing table and pen) to digitize the cross
section of a horizontal stabilizer for lightning current flow
calculations
on the mainframe and the PC's.

The above briefly describes my computer experiences while engineering
the
protection against the High Altitude Nuclear ElectroMagnetic Pulse(NEMP)
protection of the buried(Montana, Missouri, Wyoming, South Dakota...)
Minuteman nukes, and during my design of the Induced Lightning
shielding for
the fly-by-wire 777. Swords into Plowshares!

I have never used BASIC but I probably still have a few BASIC fractals
etc.
that Yehuda posted to this LogoForum a few years ago. My oldest son(40
year
old Professional Electrical Engineer) presently does some VISUAL BASIC
programming during his work. But once again, I assume this is done
during
spare moments and at home rather than during his normal work day. Dale
---
$ dale-reed@att.net Seattle, Washington USA $


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http://groups.yahoo.com/group/LogoForum

daniel ajoy

The message below is being cross-posted from LogoForum.

I want to make a comment too.

I think functional programming is not that hard if it doesn't
involve recursion. I think it is easier than "while/for"
loops. Function composition is not the problem, recursion
is what makes functional programming hard.

What I think is that novices want is a collection oriented
language, they want to be able to say things like.

generate a list of 100 coin tosses
count the heads

that is, they would want instructions that apply over the
whole object of exploration.

I think map and reduce do that but I agree than cascase is
harder to understand.

This is the way I would do it with LogoFE

show clona [100 2]
[2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
2 2 2 2 2 2 2 2 2
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
2 2 2 2 2 2 2 2 2
2 2 2 2 2 2 2 2 2 2 2]

show impon "random clona [100 2]
[0 0 1 1 0 1 0 0 1 1 1 1 1 1 0 1 0 0 1 1 1 1 1 0 1 0 0 1 1 0 1 0 1 0 1
0 0 1 1 0 1 0 0 0
0 1 0 1 1 1 0 1 1 1 0 0 0 0 1 1 1 1 1 0 0 1 1 0 0 0 0 1 0 1 1 1 0 1 0 0
1 1 1 0 1 0 1 0 0
1 0 1 1 1 0 1 0 0 1 0]

how many heads?

show suma impon "random clona [100 2]
55

Here is another thing that could be done:

show clona [100 HT]
[HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT
HT HT HT HT HT HT
HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT
HT HT HT HT HT HT
HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT HT
HT HT HT HT HT HT
HT HT HT HT HT HT HT HT HT HT HT]

show impon "pick clona [100 HT]
[T H H T H H H T T H H H T H T T T T H H H H T T T T T T H H T H H H H
H T T H H H T T H
H T H H H H T H T T T T H T H T T H T T H H T H H T T H H H T T T T H T
H T H T H H H H H
T H T T T H T T T H T]

show agrega duplica impon "pick clona [100 HT]
[[T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T
T T T T T T T T T
T] [H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H
H H H H H H H H H
H H H H H H H H H H H H]]

show impon "count agrega duplica impon "pick clona [100 HT]
[63 37]

show impon "count agrega duplica impon "pick clona [100 HT]
[54 46]

show impon "count agrega duplica impon "pick clona [100 HT]
[49 51]

Daniel

*****************************
OpenWorld Learning
http://www.openworldlearning.org


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pavel boytchev

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No assumptions at all, I *was* sure.

So you are not that bad !


And you have a formal method for deciding which *Logo* style is poor and
which is good, haven't you ?
Let me tell you something, 99.9% of all Logo programs are rather small.
The good/bad programing style you refer to, is a metric from the
industry, where programs are big, teams are big, and error consequences
are big. You cannot and should not apply them to Logo programs without
knowing in advance the goals of their authors.

This should not depend on age at all !

If I were you, I'd point out your extremely poor naming of
variables.What's that 'f', 'm' and 'n'? I'm ashamed that you have no
progress at all for the last decade. Please reread The Good Programming
Style textbook. The next time I'd expect from you to name variables
well!

I'm just kidding, of course

Regards,
Pavel


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daniel ajoy

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For example. For the task in
http://www.cs.berkeley.edu/~bh/v1ch5/hof.html
-----------
» The first task is for the computer to make a random selection from
the available colors. Write two versions: choose.dup that allows the
same color to be chosen more than once, and choose.nodup that does not
allow duplication. Each of these operations should take two inputs: a
number, indicating how many colors to choose, and a word of all the
available colors. For example, to choose four colors from the rainbow
without duplication, you'd say

? print choose.nodup 4 "roygbiv
briy
-----------

My efforts turned up this procedure:

to nd :n :x
op ( cascade :n
[word ?2 ?1] "||
[ifelse (count ?3) > 1 [pick remove ?2 ?3] [0]] pick :x
[remove ?2 ?3] :x )
end

print nd 4 "roygbiv
ygvi

print nd 4 "roygbiv
yirb

which I don't like because it uses remove twice.

Daniel

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