Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Why do you do it then?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Me Pappy used to tell me this, "do as I say, do not do as I do."

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Oh really? You Pappy seems very wise. What 'bout your Mommy?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

The funniest person that ever lived. A brilliant mathematician and chessplayer.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

**Online**

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,536

hi bobbym,

Congratulations on your 'promotion'. I think it is an excellent move by MIF.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

So your parents are/were very smart. You must have taken after them.

I'm gonna log off now and will be back in about an hour or an hour and a half.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Yes, my parents were brilliant people but they were the seed that landed on barren rock.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

That is not true. Their seed has grown into a mighty oak.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Nope, they did not make it. I wonder how many other people in the world have not made it due to not having a chance? What a waste.

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Their knowledge continues through you.You are their mighty oak.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

An oak! Maybe a little bush or hedge.

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Yes,an oak!!!

Btw,I am really getting through with the first function which is the maker of the Identity Matrix.There is although a mistake and I don't know where.Could you check my code:

```
IdenMatrix (n, matrix):=
block( [i, j, a],
i: 1,
j: 1,
while i <= n do
(
while j <= n do
(
if i = j then
a[i, j]: 1
else
a[i, j]: 0,
i: i+1,
j: j+1
)
),
matrix:genmatrix(a, n, n)
);
```

And the output is:

```
[ 1 a a ]
[ 1, 2 1, 3 ]
[ ]
(%o13) [ a 1 a ]
[ 2, 1 2, 3 ]
[ ]
[ a a 1 ]
[ 3, 1 3, 2 ]
```

*Last edited by anonimnystefy (2012-04-10 23:15:59)*

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Hi;

Good practice to code it for yourself. But I should have mentioned

that Maxima has a built in identity function.

identity(3) yields

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

But why does it put a[i,j] whenever i<>j? I set it to 0 if i<>j.

And that function doesn't work for me.I will check '?? matrix' to see if there is a function for an identity matrix.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Maxima already has a built in identity function so do not worry.

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Which function is that? Identity(n) and identity(n) don't work for me,but even if there is such a function,I want to make my own.It will be better for me.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Okay, but it is more serious that you are not getting these built in commands to work. We are trying to implement a PSLQ. If we get sidetracked we will never finish. What error message are you getting?

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

There is no error message.It just puts wrong 'numbers' into the matrix.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Hmmm. Could be a bug. What does it output for identity(2)?

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

identity(2) outputs 2.It doesn't make a matrix.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Hi;

Please go here and let's see what works and what does not.

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

Same thing, I just went to the next page.

**In mathematics, you don't understand things. You just get used to them.**

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,673

Yes

But that still doesn't help me find a function for making an identity matrix or fix my code.

Here lies the reader who will never open this book. He is forever dead.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,778

One thing at a time. The list of commands on that page I gave might work and they might not. Do they work for you?

**In mathematics, you don't understand things. You just get used to them.**

**Online**