Matlab: Matrix to a single column

Example:

a=
1 2 3
4 5 6
7 8 9

a=a(:)
->
a=
1
4
7
2
5
8
3
6
9

Matlab: Remove all the unwatned elements in matrix

Today I just got a big set of data, the record of ozone level for one year. When the data is bad or there is no data for a certain point of time , they just use a 999. So I want to remover all of the 999s in this matrix.

If use Excel, that's easy- Find and Replace. In matlab, what I did is this:

Matrix=Matrix(Matrix ~=999)

Here's a simpler example:

a=[1 2 3 4 5 6 7 8 9 ];

b=a(a~=4);

->

b=[1 2 3 5 6 7 8 9]

Casio FX4500PA Calculator User Manual Download

I got a Casio fx4500PA calculator several years ago, but I just use it for the simplest calculation. And today I realized that it might be interesting if I do some more complicated job on this calculator. So I found this user manual and it can tell me how to do INTEGRATION and other programming on it. It's pretty cool.

Here's the link to download the user manual:

Casio FX4500PA Calculator User Manual Download

Tiny URL for this blog

http://tinyurl.com/lqd2hz

Calculate Sequence and Sum

For a(1)=sqrt(2) and a(n+1)=sqrt(2+sqrt(n)), calculate the sequence and sum for n=10.

clc; clear all; close all;

format long;

a=[];

S=[];

a(1)=sqrt(2);

for k=2:11

a(k)=sqrt(2+a(k-1))

end

a=a';

for m=1:k

S(m)=sum(a(1:m));

end

3rd Movie

Well, this time I wrote the code by myself.

clc; clear all; close all;
Fig=figure;
aviobj=avifile('sphere.avi');

for k=1:6
n=2^k-1;
[x y z]=sphere(n);
c = hadamard(2^k);
surf(x, y, z, c)
colormap([1 1 0; 0 1 1]);
axis off; axis equal;
F=getframe(Fig);
for m=1:15
aviobj=addframe(aviobj, F);
end
end
for k=5:-1:1
n=2^k-1;
[x y z]=sphere(n);
c = hadamard(2^k);
surf(x, y, z, c)
colormap([1 1 0; 0 1 1]);
axis off; axis equal;
F=getframe(Fig);
for m=1:15
aviobj=addframe(aviobj, F);
end
end
close(Fig)
aviobj = close(aviobj);

Another avi 'Movie' by avifile function