Comments on: A 10 minute tutorial for solving Math problems with Maxima

By: KSO

KSO — Wed, 09 May 2012 00:38:40 +0000

I’m trying to add random noise to a function, but the random() function only generates a single number, giving me an offset. I want my function to plot a Lorentzian curve, for example, but I want random white noise added to every point, not just one. I used the following function definition:

Lno(G,x0,x):=(
r:random(x),
1/%pi*(0.5*G)/((x-x0)^2+(0.5*G)^2)+r
);

and tried another

Lnoi(G,x0,x):=1/%pi*(0.5*G)/((x-x0)^2+(0.5*G)^2)+random(1.2);

All I get is a smooth Lorentzian curve with a random offset when I plot using plot2d, not random noise at every point.

Does anyone know how to do this?

By: phobos

phobos — Tue, 08 May 2012 11:07:08 +0000

How to use if condition inside for loop.
I am using the following:

new:makelist(0);
k:1;
for i from 1 thru 10 do (
(if(imagpart(xvals[i]) = 0) then ab:makelist(xvals[i]),new:append(new,ab),k:k+1)
);

But, the if condition also gets executed 10 times.. though clearly it is not the case in my program.

By: M Kanagasabapathy

M Kanagasabapathy — Sun, 06 May 2012 05:57:17 +0000

Dear Antonio Cangiano,

Excellent and Nice tutorial. Kindly proceed for higher computations , tensors, numerical simulations etc., if possible. It can be beneficial for researchers and students.
Dr M Kanagasabapathy

By: RockyRoad

RockyRoad — Tue, 03 Apr 2012 10:31:43 +0000

Great work Antonio, thank you very much

Inspiring ? Yes !

I’m nearly new to CAS programs (played a bit with gnuplot though), my last math classes are over 25 years old now … not easy !

I’m delighted to discover what Maxima can do for me and feel eager to refresh and
and expand my math notions and practice.

Your tutorial could do that !

By: jerzy

jerzy — Sat, 10 Mar 2012 20:53:51 +0000

Clear, simple, useffull, beautiful work. Thanks.

By: jerzy

jerzy — Sat, 10 Mar 2012 20:44:33 +0000

Maxima gives correct result, because:
2*cos(x)^2 + sin(x)^2=
cos(x)^2+cos(x)^2 + sin(x)^2=
cos(x)^2+1

where
cos(x)^2 + sin(x)^2=1

By: Derek Pilous

Derek Pilous — Mon, 05 Mar 2012 22:52:50 +0000

Fantastic tutorial, thank you very much. If you’re not a teacher, you should be (well, if you’re scientist, you’re excused ). I am teacher myself and I can say, there are few people capable of writing so comprehensible and yet inspiring introduction to topic. Sorry for my English

By: Ragbir Chana

Ragbir Chana — Fri, 11 Nov 2011 14:39:17 +0000

Great tutorial. I like tutorials doing by example.

By: paulb

paulb — Tue, 13 Sep 2011 02:37:44 +0000

try

f(x):=sum(i, i, 1, x);
plot2d(f(x),[x,1,20]);

By: Antonio Cangiano

Antonio Cangiano — Tue, 06 Sep 2011 10:56:36 +0000

sum(i, i, 1, n), simpsum;